func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = pow(10, 9) + 7;   int main() {     ios_base::sync_with_stdio(false);     int k;     cin >> k;     string s;     cin >> s;     int n = s.length();     int l = 0, r = 0;     long long ans = 0LL;     long long count1 = 0;     while (l < n && k != 0) {       long long countL = 0, countr = 0;       bool found = false;       while (r < n) {         if (s[r] ==  1 ) count1++;         r++;         if (count1 == k) {           found = true;           break;         }       }       while (r < n && s[r] !=  1 ) {         countr++;         r++;       }       while (l < n && s[l] !=  1 ) {         countL++;         l++;       }       if (found) ans += (countL + 1) * (countr + 1);       count1--;       l++;     }     long long z = 0LL;     if (k == 0) {       for (int i = 0; i < n; i++) {         if (s[i] ==  0 )           z++;         else {           ans += (z * (z + 1)) / 2;           z = 0;         }       }     }     cout << (ans + (z * (z + 1)) / 2);     cout << endl;     return 0;   }   