MOD = 10**9 + 7
n = int(input())
a = list(map(int, input().split()))
if any(v == 0 for v in a):
    print(-1)
    exit()

ans = 1
for v in a:
    for j in range(1, v + 1):
        ans = ans*(pow(v, j))
        if ans > MOD:
            print(MOD)
            exit()
else:
    print(MOD % ans)