本人蒟蒻,不喜勿喷

#include <iostream>
#include <string>
using namespace std;

int main() {
    string x;
    cin >> x;
    
    int n = 0;
    int current_state = 0;

    for (int i = 0; i < x.size(); i++) {
        if ((x[i] - '0' + current_state) % 2 == 0) {
            n++;
            current_state = 1 - current_state;
        }
    }

    cout << n << endl;
    return 0;
}

求助大蛇,为啥40分