#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> x;
  int m, n, o, k, l = 0, sum = 0;
  cin >> m >> n >> o;
  for (int i = 0; i < m; i++) {
    cin >> k;
    x.push_back(k);
  }
  sort(x.rbegin(), x.rend());
  if (n <= o) {
    cout << 0;
    return 0;
  }
  int i = 0;
  while (m--) {
    o--;
    l++;
    sum += x[i];
    if (sum + o >= n) {
      cout << l;
      return 0;
    }
    i++;
  }
  cout << -1;
  return 0;
}
