usaco-practice/codeforces/Next Round/index.cpp

using namespace std;

#include <iostream>

int main() {
  int n, k;
  cin >> n >> k;
  int w;
  int a = 0;
  for (int i = 0; i < n; i++) {
    int j;
    cin >> j;
    if (j == 0) {
      break;
    }
    if (i == k - 1) {
      w = j;
      a++;
    } else if (i > k - 1) {
      if (j == w) {
        a++;
      } else {
        break;
      }
    } else {
      a++;
    }
  }
  cout << a << endl;
}