#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(),(x).end()

typedef long long ll;
typedef pair<ll, ll> P;

const int mod =  1000000007;  //出力は (ans % mod + mod) % mod  (負の剰余を正にする)
const int inf = 1e9;
const long long INF = 1LL << 60;

int dp[200050][10];

int main()
{
    int n; cin >> n;
    int a[n];
    rep(i,n){
        int x; cin >> x;
        a[i] = x%10;
    }
    for(int i = 0; i < 200050; i++){
        for(int j = 0; j < 10; j++) dp[i][j] = -inf;
    }
    dp[0][0] = 0;
    for(int i = 0; i < n; i++){
        for(int j = 0; j < 10; j++){
            if(j - a[i] >= 0) dp[i+1][j] = max(dp[i][j],dp[i][j-a[i]]+1);
            else dp[i+1][j] = max(dp[i][j],dp[i][10+j-a[i]]+1);
        }
    }
    cout << dp[n][0] << endl;
}