def CountZero(n):
    count = 0
    while n > 0:
        n = n // 5
        count += n
    return count


if __name__ == '__main__':
    n = int(input().strip())
    ans = CountZero(n)
    print(ans)

def solve(lu):
    old = [(0, 0)]
    for i in range(len(lu)):
        pos = old[-1]
        if lu[i] == 'N':
            a, b = pos[0] - 1, pos[1]
            old.append((a, b))
        elif lu[i] == 'S':
            a, b = pos[0] + 1, pos[1]
            old.append((a, b))
        elif lu[i] == 'E':
            a, b = pos[0], pos[1] + 1
            old.append((a, b))
        elif lu[i] == 'W':
            a, b = pos[0], pos[1] - 1
            old.append((a, b))
    if len(old) == len(set(old)):
        return False
    return True


if __name__ == '__main__':
    lu = input().strip()
    ans = solve(lu)
    if ans:
        print("True")
    else:
        print("False")

import collections


def solve(s):
    stack = collections.deque()
    for i in range(len(s)):
        if s[i] == '('&nbs***bsp;s[i] == '{'&nbs***bsp;s[i] == '[':
            stack.append(s[i])
        else:
            if len(stack) > 0:
                p = stack.pop()
                if (s[i] == ')' and p=='(')&nbs***bsp;(s[i] == '}' and p=='{')&nbs***bsp;(s[i] == ']' and p=='[') :
                    continue
                else:
                    return False
            else:
                return False
    return True


if __name__ == '__main__':
    s = input().strip()
    if solve(s):
        print("True")
    else:
        print("False")