#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> myvec;
  int n, x, a, s1 = 0, s2 = 0;
  cin >> n >> x;
  for (int i = 0; i < n; i++) {
    cin >> a;
    if (a < x && a >= 0) s1++;
    if (a == x) s2++;
  }
  cout << x - s1 + s2;
  return 0;
}
