from math import factorial
MOD = 10**9 + 7
N = int(input())
A = list(map(int,input().split()))
if 0 in A:
    print(-1)
    exit(0)
ans = 1
for e in A:
    if e > 10:
        print(MOD)
        exit(0)
    ans *= pow(e,factorial(e))
    if ans > MOD:
        print(MOD)
        exit(0)
if ans == 0:
    print(-1)
else:
    print(MOD%ans)