import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {
	
	public static int answer = -1;
	
	public static void dfs(final int deep, final int N, int[] items, final int M, int[] boxes, boolean[] used, int count){
		//System.out.println(deep + " " + count);
		if(deep >= N){
			//System.out.println(Arrays.toString(used));
			if(answer < 0 || answer > count){
				answer = count;
			}

			return;
		}else if(answer >= 0 && count >= answer){
			return;
		}
		
		for(int i = 0; i < M; i++){
			if(boxes[i] < items[deep]){ continue; }
			
			final boolean first_use = !used[i];
			if(first_use){ used[i] = true; }
			boxes[i] -= items[deep];
			dfs(deep + 1, N, items, M, boxes, used, count + (first_use ? 1 : 0));
			boxes[i] += items[deep];
			if(first_use){ used[i] = false; }
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		
		int[] items = new int[N];
		for(int i = 0; i < N; i++){
			items[i] = -sc.nextInt(); 
		}
		Arrays.sort(items);
		for(int i = 0; i < N; i++){
			items[i] = -items[i];
		}
		
		final int M = sc.nextInt();
		int[] boxes = new int[M];
		for(int i = 0; i < M; i++){
			boxes[i] = sc.nextInt();
		}
		
		dfs(0, N, items, M, boxes, new boolean[M], 0);
		System.out.println(answer);
		
	}

}