#include <bits/stdc++.h>
using namespace std;
vector<int> v;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, x;
  cin >> n >> x;
  for (int i = 0; i < n; i++) {
    int j;
    cin >> j;
    v.push_back(j);
  }
  sort(v.begin(), v.end());
  if (x == 0) {
    if (v[0] == 0)
      cout << 1;
    else
      cout << 0;
    exit(0);
  }
  int cnt = 0;
  int a1 = 0;
  for (int i = 0; i < n; i++) {
    if (v[i] < x) cnt++;
    if (v[i] == x) a1++;
  }
  a1 += x - cnt;
  cout << a1;
  return 0;
}
