#include <bits/stdc++.h>
using namespace std;
bool cmp(int a, int b) { return a > b; }
int main() {
  int i, j, k;
  int go[333];
  int n, m;
  cin >> n >> m >> k;
  for (i = 0; i < n; i++) cin >> go[i];
  sort(go, go + n, cmp);
  if (k >= m) {
    cout << '0' << endl;
    return 0;
  }
  for (i = 0; i < n; i++)
    if (go[i] > 1) {
      k += go[i] - 1;
      if (k >= m) {
        break;
      }
    }
  if (i >= n)
    cout << "-1" << endl;
  else
    cout << i + 1 << endl;
  return 0;
}
