#include <bits/stdc++.h>
using namespace std;

int main(void){
    int n, k;
    cin >> n >> k;
    vector<int> ct(n);
    int a;
    for (int i = 0; i < n; i++) {
        cin >> a;
        ct[a-1]++;
    }
    
    int sum = 0, ans = 0;
    for (int i = 0; i < n; i++) {
        sum += ct[i];
        if (ct[i] != 0) ans++;
        if (sum >= k) {
            break;
        }
    }
    cout << ans << endl;
}