import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

def root(N):
	val = sum(list(map(int, list(str(N)))))
	if val % 9 != 0:
		return val % 9
	elif val == 0:
		return 0
	else:
		return 9
#処理内容
def main():
	N = int(input())
	P = getlist()
	ans = 1
	for i in P:
		ans *= root(i)
		ans = root(ans)

	print(ans)


if __name__ == '__main__':
	main()