source_code: import java.io.*;
  import java.util.*;
  
  
  public class A {
      
      public static void main(String[] args) throws Exception {
          Scanner in = new Scanner(System.in);
          int n = in.nextInt();
          int m = in.nextInt();
          int k = in.nextInt();
          int so[]= new int[n];
          for(int i=0;i<n;i++) so[i]=in.nextInt();
          Arrays.sort(so);
          if(m<=k) {
              System.out.println("0");
              return;
          }
          int sum=0;
          int socUsed=0;
          int cont=0;
          for(int i=n-1;i>=0;i--){
              cont++;
              sum+=so[i]; 
              if(sum>=m || sum+(k-1)>=m){
                  System.out.println(cont);
                  return;
              }   
              sum--;  
          }   
          System.out.println("-1");
      }
  }
  