source_code: import java.util.*;
  public class a {
  public static void main(String[] args)
  {
      Scanner input = new Scanner(System.in);
      int n = input.nextInt(), m = input.nextInt(), k = input.nextInt();
      int[] data = new int[n];
      for(int i = 0; i<n; i++)
          data[i] = input.nextInt();
      Arrays.sort(data);
      m -= k;
      int at = n-1;
      int count = 0;
      while(at>=0 && m>0)
      {
          count++;
          m++;
          m -= data[at];
          at--;
      }
      if(m>0)
          System.out.println(-1);
      else
          System.out.println(count);
  }
  }
  