#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x, i, j, k = 0;
  cin >> n >> x;
  int s[n];
  j = 0;
  for (i = 0; i < n; i++) cin >> s[i];
  sort(s, s + n);
  for (i = 0; i < n; i++) {
    if (s[i] < x)
      j++;
    else if (x == s[i])
      k = 1;
  }
  cout << x - j + k;
  return 0;
}
