n = int(input())
a = list(map(int,input().split()))
if 0 in a:
    print(-1)
    exit()
mod = 10**9+7
count = 1
for i in a:
    if i >= 4:
        print(mod)
        exit()
    x = 1
    for j in range(1,i+1):
        x *= j
    count *= pow(i,x)
    if count > mod:
        print(mod)
        exit()
print(mod%count)