# No.1237 EXP Multiple!
# https://yukicoder.me/problems/no/1237

from math import factorial

def f(x):
  return x ** factorial(x)

n = int(input())
A = list(map(int, input().split()))

MOD = 10 ** 9 + 7

if any(a == 0 for a in A):
  print(-1)
  exit()

if any(a > 9 for a in A):
  print(MOD)
  exit()

ans = 1
for a in A:
  if ans >= MOD:
    print(MOD)
    exit()
  ans *= f(a)

print(MOD % ans)