import sys
input = sys.stdin.readline
N = int(input())
a = list(map(int, input().split()))
a.sort()
mod = 10 ** 9 + 7
q = 1
for x in a:
  if x == 1: continue
  if x == 0:
    q = 0
    break
  t = x
  for i in range(1, x + 1):
    t = pow(t, i)
    if q * t > mod:
      print(mod)
      exit(0)
  q *= t
if q > 0: print(mod % q)
else: print(-1)