#include <bits/stdc++.h>

using namespace std;

int main() {
  int n, m;
  cin >> n >> m;
  priority_queue<int, vector<int>, greater<int> > q;  
  for (int i = 0; i < n; ++i) {
    int c;
    cin >> c;
    q.push(c);
  }
  int ans = 0;
  while (m--) {
    int cur = q.top(); q.pop();
    cur--;
    if (cur == 0) ans++;
    else q.push(cur);
  }
  cout << ans << '\n';
}