from math import factorial
n = int(input())
a = list(map(int, input().split()))
a.sort()
if 0 in a:
    exit(print(-1))
ans = 1
for i in range(n):
    if a[i] >= 18:
        exit(print(10 ** 9 + 7))
    ans *= pow(a[i], factorial(a[i]))
    if ans >= 10 ** 9 + 7:
        exit(print(10 ** 9 + 7))
print((10 ** 9 + 7) % ans)