import itertools as it
N = int(raw_input())
A = map(int,raw_input().split())
M = int(raw_input())
oB = sorted(map(int,raw_input().split()),reverse = True)
ans = 100
for order in it.permutations(A,N):
    B = oB[:]
    i = j = 0
    while max(i,j) < N:    
        if B[j] >= A[j]:
            B[j] -= A[i]
            i += 1
        else:
            j += 1
        if i == N:
            ans = min(ans, j+1)
print ans if ans < 100 else -1