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

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


def excess(flag):
    if flag:
        print(DIV)
        exit()


ans = 1
for a in A:
    excess(a >= 4)
    tmp = 1
    for i in range(1, a + 1):
        tmp *= i
    ans *= a ** tmp
    excess(ans > DIV)
print(DIV % ans)