#include <bits/stdc++.h>
using namespace std;
void solution() {
  int n, x;
  cin >> n >> x;
  int cnt = 0, pr = 0;
  for (int i = 1; i <= n; i++) {
    int lik;
    cin >> lik;
    if (lik < x) {
      cnt++;
    } else if (lik == x) {
      pr = 1;
    }
  }
  int ans = x - cnt;
  if (pr == 1) ans++;
  cout << ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  solution();
  return 0;
}
