#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  long long n, x;
  cin >> n >> x;
  vector<long long> vec(n);
  for (long long i = 0; i < n; i++) cin >> vec[i];
  sort(vec.begin(), vec.end());
  long long ind = -1;
  long long less = 0;
  for (long long i = 0; i < n; i++) {
    if (vec[i] == x) ind = i;
    if (vec[i] < x) less++;
  }
  long long cnt = (x - less) + (ind >= 0);
  cout << cnt << endl;
}
