#include <bits/stdc++.h>
using namespace std;
int p[200000];
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) cin >> p[i];
  int pos1 = -1;
  for (int i = 0; i < n; i++)
    if (p[i] == 1) pos1 = i;
  cout << min(pos1 + 1 - k + 1, n - pos1 - k + 1);
}
