N=int(input())
A=list(map(int,input().split()))
M=int(input())
B=list(map(int,input().split()))

B.sort(reverse=True)

def check(A,B):
    if sum(A)==0:
        return 1
    
    if sum(A)>sum(B):
        return 0

    ANS=0

    A=list(A)
    B=list(B)

    for i in range(len(B)):
        if B[i]>=A[0]:
            B[i]-=A[0]
            if check(tuple(A[1:]),tuple(B))==1:
                ANS=1
            B[i]+=A[0]
    return ANS

ANS=-1
for i in range(len(B)+1):
    if check(A,B[:i])==1:
        ANS=i
        break
print(ANS)