diff --git a/Check_Odd_Even.py b/Check_Odd_Even.py
deleted file mode 100644
index 87c2d8d..0000000
--- a/Check_Odd_Even.py
+++ /dev/null
@@ -1,10 +0,0 @@
-# -------------------------------------
-# create by: Nguyen Tien Dung         -
-# Date: 10:11 PM 30/8/2021             -
-# ------------------------------------
-
-numbe = int(input())
-if numbe % 2 == 0:
-    print("CHAN")
-else :
-    print("LE")
\ No newline at end of file
diff --git a/Decode.py b/Decode.py
deleted file mode 100644
index 06dc7c3..0000000
--- a/Decode.py
+++ /dev/null
@@ -1,17 +0,0 @@
-# -------------------------------------
-# create by: Nguyen Tien Dung         -
-# Date: 11:23 PM 30/8/2021            -
-# -------------------------------------
-#hehelo bebe
-T = int(input())
-while T>0:
-    str = input()
-    for index in range(len(str)):
-        if index % 2 == 1:
-            k = int(str[index])
-            # print(str[index])
-            while k > 0:
-                print(str[index-1],end="")
-                k = k-1
-    T = T-1
-    print("\n")
\ No newline at end of file
diff --git a/Decode_1.py b/Decode_1.py
new file mode 100644
index 0000000..9c40aad
--- /dev/null
+++ b/Decode_1.py
@@ -0,0 +1,21 @@
+T = int(input())
+while T > 0:
+    s = ""
+    st = str(input())
+    cnt = 1
+    k = len(st)
+    for i in range(0,k-1,1):
+        if st[i] == st[i+1]:
+            cnt = cnt+1
+        else:
+            sTmp = str(cnt) + st[i]
+            s = s+sTmp
+            cnt = 1
+    if st[k-1] != st[k-2]:
+        sTmp = '1' + st[k-1]
+        s = s+sTmp
+    else:
+        sTmp = str(cnt) + st[k-1]
+        s= s+sTmp
+    print(s)
+    T = T - 1
\ No newline at end of file
diff --git a/Even_Odd.py b/Even_Odd.py
new file mode 100644
index 0000000..08709e5
--- /dev/null
+++ b/Even_Odd.py
@@ -0,0 +1,23 @@
+T = int(input())
+while T>0:
+    str = input()
+    sum = 0
+    check = 1
+    # t = abs(int(str[0]) - int(str[1]))
+    # print(type(t))
+    for index in range(len(str)-1):
+        if abs(int(str[index]) - int(str[index+1])) == 2:
+            sum = sum + int(str[index])
+        else:
+            check = 0
+            break
+    if(check == 0):
+        print("NO")
+    else:
+        sum = sum + int(str[len(str)-1])
+        if sum % 10 == 0:
+            print("YES")
+        else:
+            print("NO")
+    # print(sum)
+    T = T-1
diff --git a/First_Last.py b/First_Last.py
new file mode 100644
index 0000000..4497372
--- /dev/null
+++ b/First_Last.py
@@ -0,0 +1,12 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 11:20 PM 31/8/2021            -
+# -------------------------------------
+T = int(input())
+while T > 0:
+    str = input()
+    if str[0] == str[len(str)-2] and str[1] == str[len(str)-1]:
+        print("YES")
+    else:
+        print("NO")
+    T = T - 1
diff --git a/Insert_Comma.py b/Insert_Comma.py
new file mode 100644
index 0000000..6f3178d
--- /dev/null
+++ b/Insert_Comma.py
@@ -0,0 +1,9 @@
+# for i in range(5,-1,-1):
+#     print(i)
+# systax
+# str = str1[:index] + str2 + str1[index:]
+str = input()
+# print(len(str))
+for i in range(len(str)-3,0,-3):
+    str = str[:i] + "," + str[i:]
+print(str)
\ No newline at end of file
diff --git a/Insert_String.py b/Insert_String.py
new file mode 100644
index 0000000..652e68b
--- /dev/null
+++ b/Insert_String.py
@@ -0,0 +1,7 @@
+str1 = input()
+str2 = input()
+index = int(input())
+index = index-1
+# def insert_sequence(str1, str2, index):
+str = str1[:index] + str2 + str1[index:]
+print(str)
\ No newline at end of file
diff --git a/Inversion_Pair.py b/Inversion_Pair.py
new file mode 100644
index 0000000..f8cbd38
--- /dev/null
+++ b/Inversion_Pair.py
@@ -0,0 +1,25 @@
+# create by: Nguyen Tien Dung         -
+# Date: 10:35 PM 31/8/2021            -
+# -------------------------------------
+# import array as arr
+#
+# a = arr.array('i', [])
+#
+# k = int(input("Enter size of array:"))
+# for i in range(0, k):
+#     num = int(input())
+#     a.append(num)
+# cnt = 0
+# for i in range(0,k-1):
+#     for j in range(i,k):
+#         if a[i] > a[j]:
+#             cnt = cnt + 1
+# print(cnt)
+T = int(input())
+str = [int(x) for x in input().split()]
+cnt = 0
+for i in range(len(str)-1):
+    for j in range(i+1,len(str)):
+        if int(str[i]) > int(str[j]):
+            cnt = cnt + 1
+print(cnt)
\ No newline at end of file
diff --git a/Lucky_Number.py b/Lucky_Number.py
new file mode 100644
index 0000000..0c66e8f
--- /dev/null
+++ b/Lucky_Number.py
@@ -0,0 +1,13 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 11:24 PM 30/8/2021            -
+# -------------------------------------
+T = int(input())
+while T>0:
+    str = input()
+    k = len(str)
+    if(str[k-1] == '6' and str[k-2] == '8'):
+        print("YES")
+    else:
+        print("NO")
+    T = T-1
diff --git a/Lucky_Number_1.py b/Lucky_Number_1.py
new file mode 100644
index 0000000..eb764ac
--- /dev/null
+++ b/Lucky_Number_1.py
@@ -0,0 +1,9 @@
+str = input()
+cnt = 0
+for i in range(len(str)):
+    if str[i] == '4' or str[i] == '7':
+        cnt = cnt+1
+if cnt == 4 or cnt == 7:
+    print("YES")
+else:
+    print("NO")
\ No newline at end of file
diff --git a/Lucky_Number_2.py b/Lucky_Number_2.py
new file mode 100644
index 0000000..ad59dac
--- /dev/null
+++ b/Lucky_Number_2.py
@@ -0,0 +1,13 @@
+T = int(input())
+while T>0:
+    check = 0
+    str = input()
+    for i in range(len(str)):
+        if str[i] != '4' and str[i] != '7':
+            check = 1
+            break
+    if check == 0:
+        print("YES")
+    else:
+        print("NO")
+    T = T - 1
\ No newline at end of file
diff --git a/Matching_Number.py b/Matching_Number.py
new file mode 100644
index 0000000..37368fd
--- /dev/null
+++ b/Matching_Number.py
@@ -0,0 +1,18 @@
+T = int(input())
+while T>0:
+    n = int(input())
+    str1 = [int(x) for x in input().split()]
+    str2 = [int(x) for x in input().split()]
+    str1.sort()
+    str2.sort()
+    check = 0
+    for i in range(0,n,1):
+        if str1[i] > str2[i]:
+            check = 1
+            break
+
+    if check == 1:
+        print("NO")
+    else:
+        print("YES")
+    T = T - 1
\ No newline at end of file
diff --git a/MostFrequent.py b/MostFrequent.py
new file mode 100644
index 0000000..6da921b
--- /dev/null
+++ b/MostFrequent.py
@@ -0,0 +1,33 @@
+# T = int(input())
+# while T > 0:
+#     n = int(input())
+#     str = input()
+#     str = str.replace(" ","")
+#     maxi  = 0
+#     for i in range(0,len(str),1):
+#         d[str[i]] = d[str[i]] + 1
+#         if d[str[i]] >  maxi:
+#             maxi = d[str[i]]
+#     T = T - 1
+#     print(maxi)
+#     TLE
+T = int(input())
+while T>0:
+    n = int(input())
+    str = input()
+    str = str.split()
+    list_1 = []
+    list_1[:0] = str
+    dict = {}
+    count,itm = 0,''
+    for item in reversed(list_1):
+        dict[item] = dict.get(item,0)+1
+        if dict[item] >= count:
+            count,itm = dict[item],item
+
+    k = list_1.count(itm)
+    if k > len(str)//2:
+        print(itm)
+    else:
+        print("NO")
+    T = T - 1
diff --git a/No_Decrease.py b/No_Decrease.py
new file mode 100644
index 0000000..e9c3ade
--- /dev/null
+++ b/No_Decrease.py
@@ -0,0 +1,18 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 10:30 PM 30/8/2021            -
+# -------------------------------------
+T = int(input())
+while T>0:
+    str = input()
+    check = 0
+    for index in range(len(str)-1):
+        if int(str[index]) > int(str[index+1]):
+                check = 1
+                break
+    if check == 0:
+        print("YES")
+    else:
+        print("NO")
+    T = T-1
+    print("\n")
diff --git a/Prime.py b/Prime.py
new file mode 100644
index 0000000..3eb7284
--- /dev/null
+++ b/Prime.py
@@ -0,0 +1,16 @@
+import math
+
+T = int(input())
+
+while T>0:
+    n = int(input())
+    check = 0
+    for i in range(2,int(math.sqrt(n))+1,1):
+        if n%i == 0:
+            check = 1
+            break
+    if check == 0:
+        print("YES")
+    else:
+        print("NO")
+    T = T - 1
\ No newline at end of file
diff --git a/Prime_1.py b/Prime_1.py
new file mode 100644
index 0000000..f36528f
--- /dev/null
+++ b/Prime_1.py
@@ -0,0 +1,34 @@
+import math
+
+def Sieve(h):
+    prime = [True for x in range(h + 1)]
+    p = 2
+    while p * p <= h:
+        if prime[p]:
+            for j in range(p * p, h + 1, p):
+                prime[j] = False
+        p += 1
+    prime[0] = False
+    prime[1] = False
+    cnt = 0
+    for j in range(2, h + 1):
+        if prime[j]:
+            cnt += 1
+    return cnt
+#hello bebe
+T = int(input())
+while T > 0:
+    n = int(input())
+    k = Sieve(n)
+    flag = True
+    if k < 2:
+        flag = False
+    for i in range(2, int(math.sqrt(k)) + 1, 1):
+        if k % i == 0:
+            flag = False
+            break
+    if flag:
+        print("YES")
+    else:
+        print("NO")
+    T -= 1
diff --git a/Sum_Number.py b/Sum_Number.py
new file mode 100644
index 0000000..c81d730
--- /dev/null
+++ b/Sum_Number.py
@@ -0,0 +1,18 @@
+T = int(input())
+while T>0:
+    s = input()
+    n = len(s)
+    sum = 0
+    s1 = ""
+    for i in range(n):
+        if s[i].isnumeric() == True:
+            sum += int(s[i])
+    for i in range(n):
+        if s[i].isnumeric() != False:
+            continue
+        else:
+            s1 = s1 + s[i]
+    s2 = sorted(s1)
+    s1 = "".join(s2)
+    print(s1+str(sum))
+    T -= 1
\ No newline at end of file
diff --git a/Summation.py b/Summation.py
new file mode 100644
index 0000000..f817723
--- /dev/null
+++ b/Summation.py
@@ -0,0 +1,10 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 10:23 PM 30/8/2021             -
+# ------------------------------------
+str = input()
+if int(str[0]) + int(str[4]) == int(str[8]):
+    print("YES")
+else:
+    print("NO")
+
diff --git a/Test.py b/Test.py
new file mode 100644
index 0000000..fb8d067
--- /dev/null
+++ b/Test.py
@@ -0,0 +1,4 @@
+ar = [int(x) for x in input().split()]
+n = len(ar)
+for i in range(n):
+    print(i)
\ No newline at end of file
diff --git a/Transform_Number.py b/Transform_Number.py
new file mode 100644
index 0000000..4eaba0c
--- /dev/null
+++ b/Transform_Number.py
@@ -0,0 +1,38 @@
+k = 10
+while k > 0:
+    ar = [int(x) for x in input().split()]
+    n = len(ar)
+    ch = True
+    for i in range(n):
+        if ar[i] != 0:
+            ch = False
+    if ch == True:
+        break
+    cnt = 0
+    t = 5
+    check = 0
+    while t>0:
+        x = ar[0]
+        for i in range(n-1):
+            ar[i] = abs(ar[i] - ar[i+1])
+
+        ar[n-1] = abs(ar[n-1] - x)
+        cnt += 1
+        ok = True
+        for i in range(n):
+            if ar[i] != 0:
+                ok = False
+                break
+        if ok == True:
+            t = 0
+    # print(cnt)
+    print(cnt-1)
+
+# //1 3 5 9
+# //2 2 4 8
+# //0 2 4 6
+# //2 2 2 6
+# //0 0 4 4
+# //0 4 0 4
+# //4 4 4 4
+# //0 0 0 0
\ No newline at end of file
diff --git a/Upper_Lower.py b/Upper_Lower.py
new file mode 100644
index 0000000..eaba532
--- /dev/null
+++ b/Upper_Lower.py
@@ -0,0 +1,17 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 11:42 PM 30/8/2021            -
+# -------------------------------------
+str = input()
+up,lo = 0,0
+for index in range(len(str)):
+    if str[index] >= 'a':
+        lo = lo + 1
+    else:
+        up = up + 1
+if up > lo:
+    print(str.upper())
+elif lo >= up:
+    print(str.lower())
+
+
diff --git a/WelcomeToPython.py b/WelcomeToPython.py
new file mode 100644
index 0000000..791401a
--- /dev/null
+++ b/WelcomeToPython.py
@@ -0,0 +1,7 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 11:44 PM 30/8/2021            -
+# -------------------------------------
+
+str = input()
+print("Hello "+str+"!")
\ No newline at end of file
diff --git a/Word_Separation.py b/Word_Separation.py
new file mode 100644
index 0000000..afb64c8
--- /dev/null
+++ b/Word_Separation.py
@@ -0,0 +1,10 @@
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 10:30 PM 30/8/2021            -
+# -------------------------------------
+
+str = input()
+str = str.split()
+for index in str:
+    print(index);
+    print("\n")
\ No newline at end of file
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..b9d1800
--- /dev/null
+++ b/main.py
@@ -0,0 +1,15 @@
+# message = "Hello Python "
+# print(message)
+# message = "Anh yeu em"
+# print(message)
+# message_1 = "co chac yeu la day"
+# print(message_1.title())
+# print(message_1.upper())
+# message_2 = "THAI BINH MO HOI ROI"
+# print(message_2.lower())
+# -------------------------------------
+# create by: Nguyen Tien Dung         -
+# Date: 9:11 PM 30/8/2021             -
+# -------------------------------------
+message = input()
+print(message.upper())