#include <bits/stdc++.h>   using namespace std;   int main() {     char s[200001], t1[200001];     long long n, x, y, t, con = 0;     cin >> n >> x >> y;     getchar();     gets(s);     t = n - x;     for (long long i = t; s[i] !=   0 ; i++) {       if (i == n - 1 - y && s[i] !=  1 ) con++;       if (i != n - 1 - y && s[i] !=  0 ) con++;     }     cout << con << endl;     return 0;   }   