import sequtils,strutils,algorithm

var
    N = stdin.readline.parseInt
    A = stdin.readline.split.map(parseInt)
    M = stdin.readline.parseInt
    B = stdin.readline.split.map(parseInt)
    cnt = M + 1
    F : array[2048,bool]
F[0] = true
B.sort(system.cmp)
B.reverse
A.sort(system.cmp)
A.reverse

proc hantei(X : openarray[int]):bool =
    if X.len == 0:
        return false
    var flag = F
    for b in X:
        var flag2 = flag
        for i in 0..<(1 shl N):
            var n = b
            var f = true
            for k,a in A:
                if (i and (1 shl k)) > 0:
                    n -= a
                    if n < 0:
                        f = false
                        break
            if f == true:
                for j in 0..<(1 shl N):
                    if flag[j] == true:
                        flag2[j or i] = true
        flag = flag2
    return flag[(1 shl N) - 1]
        

while hantei(B):
    discard B.pop
    cnt -= 1
if cnt <= M:
    echo cnt
else:
    echo -1