#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, X, aux;
  cin >> N >> X;
  int resp = X;
  for (int i = 0; i < N; i++) {
    cin >> aux;
    if (aux < X)
      resp--;
    else if (aux == X)
      resp++;
  }
  cout << resp << endl;
  return 0;
}
