source_code: 
  import java.util.Arrays;
  import java.util.Scanner;
  
  /**
   *
   * @author Natasha
   */
  public class Main{
  
      public static void main(String[] args) {
          Scanner in = new Scanner(System.in);
          int produzeni = in.nextInt();
          int devices = in.nextInt();
          int stekovi = in.nextInt();
          int [] filter = new int[produzeni];
          for(int i = 0; i<produzeni; i++){
              filter[i] = in.nextInt();
          }
          Arrays.sort(filter);
          int filt_no = filter.length-1;
          if(devices<=stekovi) {
              System.out.println("0");
              return;
          }
          int used = 0;
          while(devices>stekovi){
              try{
              stekovi+=filter[filt_no--]-1;
              }
              catch(Exception e){
                  System.out.println("-1");
                  return;
              }
          }
          
          System.out.println(filter.length - filt_no-1);
          
          
          
      }
  }
  