import java.util.*;
class main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        int n =sc.nextInt();
        int[] arr=new int[n];
        for(int i=0;i<n;i++){
            arr[i] =sc.nextInt();
        }
        int target=sc.nextInt();
        
        
        Arrays.sort(arr);
        int e =n-1;
        int cnt =0;
         while(target>0 && e>=0)
         {  
             if(arr[n-1]>target){
                 System.out.prinln(-1);
                 return;
             }
             while(arr[e]>target)
             {
                 e--;
             }
             while(target -arr[e] > arr[e])
             {
                 target = target -arr[e];
                 cnt++;
             }
             e--;
             
         }
    
      System.out.println(cnt-1);
        
    }
    
    
    
}