Untitled

#include <bits/stdc++.h>
using namespace std;
int main() {
    freopen("stone.in", "r", stdin);
    freopen("stone.out", "w", stdout);
    int k, n;
    cin >> n >> k;
    string s;
    cin >> s;
    int f[1000001];
    memset(f, 0x3f, sizeof(f));
    f[1] = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= k; j++) {
            if (i - j < 1) break;
            if (s[i - j - 1] == '0') continue;
            f[i] = min(f[i], f[i - j] + 1);
        }
    }
    cout << f[n] << endl;
    return 0;
}