题解

#include <bits/stdc++.h>
using namespace std;
int c(int d) {
    if (d == 0) return 0;
    int count = 0;
    while (d % 2 == 0) {
        count++;
        d /= 2;
    }
    return count;
}

int main() {
    string s;
    cin >> s;
    int k = s.length() - 1;
    int d = s[0] - '0';
    cout << k + c(d) << endl;
    
    return 0;
}