#include <bits/stdc++.h>
template <typename T>
std::istream& operator>>(std::istream& input, std::vector<T>& v) {
  for (T& a : v) input >> a;
  return input;
}
void answer(unsigned v) { std::cout << v << '\n'; }
void solve(std::vector<unsigned>& a, unsigned x) {
  std::sort(a.begin(), a.end());
  const size_t k = std::lower_bound(a.cbegin(), a.cend(), x) - a.cbegin();
  if (k < a.size() && a[k] == x)
    answer(x - k + 1);
  else
    answer(x - k);
}
int main() {
  size_t n;
  std::cin >> n;
  unsigned x;
  std::cin >> x;
  std::vector<unsigned> a(n);
  std::cin >> a;
  solve(a, x);
  return 0;
}
