#include <bits/stdc++.h>
using namespace std;
int s[110];
int main() {
  int n, m, k;
  while (cin >> n >> m >> k) {
    int ans = -1;
    for (int i = 1; i <= n; i++) cin >> s[i];
    sort(s + 1, s + 1 + n);
    int sum = k, cnt = 0;
    if (k >= m) {
      cout << 0 << endl;
      continue;
    }
    for (int i = n; i >= 1; i--) {
      sum += s[i];
      ++cnt;
      if (sum - cnt >= m) {
        ans = cnt;
        break;
      }
    }
    cout << ans << endl;
  }
  return 0;
}
