#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;

int main() {
  int n, c;
  cin >> n >> c;
  vector<int> v(n);
  for(auto& x: v) cin >> x;
  sort(v.begin(), v.end());
  c *= 5;
  int ret = 0;
  for(int out: v) {
    if(out <= c) {
      c -= out;
      ret++;
    }
  }
  cout << ret << "\n";
}