import sys
readline = sys.stdin.readline

N = int(readline())
P = list(map(int,readline().split()))

if 0 in P:
  print(0)
  exit(0)
  
P = list(map(lambda x:9 if x % 9 == 0 else x % 9, P))

from functools import reduce

r = reduce(lambda a,b:9 if (a * b) % 9 == 0 else (a * b) % 9, P)

print(r)