n = int(input())
A = list(map(int, input().split()))
mod = 10**9 + 7

if min(A) == 0:
    print(-1)
elif max(A) >= 4:
    print(mod)
else:
    ans = 1
    for i in range(n):
        cnt = 1
        for j in range(1, A[i] + 1):
            cnt *= j
        ans *= pow(A[i], cnt)
    print(mod % ans)