#include <iostream>
#include <cstdio>

using namespace std;

int main() {
    int n, k; cin >> n >> k;
    int old = 10000;
    for (int i = 0; i < n; i++) {
        int tmp; cin >> tmp;
        if (tmp == 0) {
            cout << i << endl;
            return 0;
        }
        if (i < k) {
            old = tmp;
            continue;
        } else {
            if (old != tmp) {
                cout << i << endl;
                return 0;
            }
        }
    }
    cout << n << endl;
    return 0;
}