import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
    final static Integer DEL_VALUE = new Integer(99);
    
    public static void main(String[] args) {
        try (Scanner scan = new Scanner(System.in)) {
            int n = Integer.parseInt(scan.next());
            ArrayList<Integer> a = new ArrayList<>();
            for(int i=0; i<n; i++) {
                a.add(Integer.parseInt(scan.next()));
            }
              
            int m = Integer.parseInt(scan.next());
            ArrayList<Integer> b = new ArrayList<>();
            for(int i=0; i<m; i++) {
                b.add(Integer.parseInt(scan.next()));
            }
            
            a.sort(Collections.reverseOrder());
            b.sort(Collections.reverseOrder());
            
            LinkedList< ArrayList<Integer> > checkList = new LinkedList<>();
            LinkedList< ArrayList<Integer> > nextCheckList = new LinkedList<>();
            checkList.add(a);
            
            for(int i=0; i<b.size(); i++) {
                
                while(!checkList.isEmpty()) {
                    final ArrayList<Integer> nowList = checkList.poll();
                    ArrayList<String> p = getPermutationList(b.get(i), nowList);
                    
                    for(String flag : p) {
                        ArrayList<Integer> tmpList = (ArrayList<Integer>)nowList.clone();
                        
                        for(int j=0; j<tmpList.size(); j++) {
                            if(flag.charAt(j) == '1') {
                                tmpList.set(j, DEL_VALUE);
                            }
                        }
                        while( tmpList.indexOf(DEL_VALUE) >= 0 ) {
                            tmpList.remove(DEL_VALUE);
                        }
                        if(tmpList.size() == 0) {
                            System.out.println(i+1);
                            System.exit(0);
                        }
                        nextCheckList.add(tmpList);
                    }
                }
                
                checkList = (LinkedList< ArrayList<Integer> >)nextCheckList.clone();
                nextCheckList.clear();
            }
            System.out.println(-1);
        }        
    }
        
    static ArrayList<String> getPermutationList(final int BOX_SIZE, ArrayList<Integer> a) {
        ArrayList<String> pList = new ArrayList<>();
        
        int n = (int)Math.pow(2, a.size());
        for(int i=n-1; i>=0; i--) {
            String flag = Integer.toBinaryString(i);
            int len = (a.size()-flag.length());
            for(int j=0; j<len; j++) flag = "0" + flag;
            
            int sum = 0;
            for(int j=0; j<a.size(); j++) {
                if(flag.charAt(j) == '1') {
                    sum += (a.get(j));
                    if(sum > BOX_SIZE) break;
                }
            }
            if(sum <= BOX_SIZE) {
                pList.add(flag);
                if(pList.size() >= 5) break;
            }
        }        
        return pList;
    }
}