#include <bits/stdc++.h>
using namespace std;
template <typename T>
void out(T x) {
  cout << x << endl;
  exit(0);
}
const int maxn = 1e6 + 5;
int n, x;
multiset<int> ms;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> x;
  for (int i = 0; i < n; i++) {
    int y;
    cin >> y;
    ms.insert(y);
  }
  int edits = 0;
  for (int j = 0; j < x; j++) {
    if (ms.count(j) == 0) edits++;
  }
  edits += ms.count(x);
  out(edits);
  return 0;
}
