#include <bits/stdc++.h>
using namespace std;
int arr[100005];
int main() {
  int n, x, ans = 0, a = 0;
  cin >> n >> x;
  for (int i = 0; i < n; i++) cin >> arr[i];
  sort(arr, arr + n);
  for (int i = 0; i < n; i++) {
    if (arr[i] < x)
      a++;
    else if (arr[i] == x)
      ans++;
    else
      break;
  }
  cout << ans + x - a;
}
