"""
[19880: Номер страницы](https://www.acmicpc.net/problem/19880)
Tier: Bronze 2
Category: 구현, 문자열
"""
def solution(s):
n = len(s)
ans = 0
if s[0] == '0':
return 0
for i in range(1, n // 2 + 1):
if s[i] == '0':
continue
if i + i < n:
ans += 1
continue
if i == n - i and s[:i] <= s[i:]:
ans += 1
return ans
if __name__ == '__main__':
print(solution(input()))