N = int(input())
A = tuple(map(int, input().split()))
DIV = 10 ** 9 + 7

if 0 in A:
    print(-1)
    exit()

ans = 1
for a in A:
    if a >= 4:
        # 10e9+7を答で割る？
        print(DIV)
        exit()
    for i in range(1, a + 1):
        ans *= a ** i
    if ans > DIV:
        print(DIV)
        exit()
print(DIV % ans)