Tech gig - count upper and lower cases in c++

#include <iostream>
using namespace std;

int main()
{
    int i;
    int upper=0,lower=0;
    char ch[100];
    cin.get(ch,100);

    for(i=0; ch[i]!=0; i++){

if(ch[i]>='A' && ch[i]<='Z'){
    upper++;
}
else if(ch[i]>='a' && ch[i]<='z'){
    lower++;
}
    }
cout<<upper<<endl;
cout<<lower<<endl;
    return 0;
}