g = [1,1,2,6]

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

if 0 in A:
    print(-1)
else:
    res = 1
    for i in range(N):
        if A[i]>=4:
            exit(print(10**9+7))
        else:
            res *= pow(A[i],g[A[i]])
            if res >= 10**9+7:
                exit(print(10**9+7))
    print((10**9+7)%res)