N = int(input())
A = list(map(int, input().split()))
inf = 10**9

dp = [-inf] * 10
dp[0] = 0

for a in A:
    nxt = [-inf] * 10
    for i in range(10):
        x = (i + a) % 10
        nxt[x] = dp[i] + 1
    dp = [max(x, y) for x, y in zip(dp, nxt)]

print(dp[0])