#make a muptiple of ten

def main():
    N = int(input())
    a = list(map(int, input().split()))
    dp = [[0 for i in range(10)] for j in range(N+1)]
    #dp[X][mod] = index-Xまで見てそれまでの総和がmod である時、これまでで取れる枚数の最大値
    for i in range(10):
        dp[1][i] = -10**18
    dp[1][a[0]%10] = 1        
    for i in range(1,N):
        v = a[i] 
        for j in range(10):
            dp[i+1][j] = max(dp[i][(j-v) % 10]+1, dp[i][j])
    ans = dp[N][0]
    print(max(ans,0))
    return


if __name__ == "__main__":
    main()