#include <iostream>
#include <vector>
#include <algorithm>
#include <math.h>
#include <iomanip>
#include <string>
using namespace std;

using ll = long long;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)	
#define max (ll)1e18
#define debug(x) cerr << #x << ": " << x << "\n"

int main() {
	ios::sync_with_stdio(false);cin.tie(0);
	
	string c;
	cin >> c;
	int cnt = 0;
	for (int i = 1; i < c.length(); i++) {
		string t1 = c.substr(0, i);
		string t2 = c.substr(i, c.length() - i);
		if (t1[0] != '0' && t2[0] != '0') {
			cnt++;
		}
	}
	cout << cnt << endl;

	return 0;
}