#include <bits/stdc++.h>
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using P = pair<ll, ll>;
const long double PI = acos(-1.0L);
ll GCD(ll a, ll b) { return b?GCD(b, a%b):a; }
ll LCM(ll a, ll b) { return a/GCD(a, b)*b; }


int main() {
    int n; cin >> n;
    vector<ll> avec(n, 0);
    for(int i = 0; i < n; ++i) cin >> avec[i];

    vector< vector<int> > dp(n+1, vector<int>(15, 0));
    for(int i = 0; i < n; ++i) {
        chmax(dp[i+1][avec[i]%10], 1);
        for(int j = 0; j < 10; ++j) {
            if(dp[i][j] > 0) chmax(dp[i+1][(j+avec[i])%10], dp[i][j]+1);
            chmax(dp[i+1][j], dp[i][j]);
        }
    }

    cout << dp[n][0] << endl;
}