proofSlice = (3, 5)
numLeaves = 7

def size(st):
    return st[1] - st[0]

def inside(point, st):
    return st[0] <= point < st[1]

def overlaps(st):
    return inside(st[0], proofSlice) or inside(proofSlice[0], st)

stack = []

def combine():
    right = stack.pop()
    left = stack.pop()
    if overlaps(right) and not overlaps(left):
        print(left)
    if overlaps(left) and not overlaps(right):
        print(right)
    st2 = (left[0], right[1])
    stack.append(st2)

for i in range(numLeaves):
    st = (i, i+1)
    stack.append(st)
    while len(stack) > 1 and size(stack[-2]) == size(stack[-1]):
        combine()
while len(stack) > 1:
    combine()