N = int(input())
A = list(map(int,input().split()))
data = [0 for i in range(10)]
for a in A:
    data[a%10]+=1

dp = [-1 for i in range(10)]
dp[0] = 0
for i in range(10):

    sub = [-1 for i in range(10)]
    for j in range(9,-1,-1):
        if data[i]>=j:
            tmp = (i*(data[i]-j)) % 10
            sub[tmp] = data[i] - j

    ndp = [-1 for i in range(10)]
    for j in range(10):
        for k in range(10):
            tmp = (j + k)%10
            if dp[j]!=-1 and sub[k]!=-1:
                ndp[tmp] = max(ndp[tmp],dp[j]+sub[k])

    dp = ndp

print(dp[0])