#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x;
  int a[110];
  while (~scanf("%d%d", &n, &x)) {
    int ans = 0;
    for (int i = 0; i < n; i++) scanf("%d", &a[i]);
    sort(a, a + n);
    for (int i = n; i <= x; i++) a[i] = -1;
    int k = 0;
    for (int i = 0;;) {
      if (k == x) {
        while (a[i] == k) {
          ans++;
          i++;
        }
        break;
      }
      if (a[i] != k) {
        ans++;
        k++;
      } else {
        k++;
        i++;
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}
