#include <bits/stdc++.h>
const long long LINF=1e18;
using namespace std;
//-------------------------↓↓↓↓↓↓------------------------

int main(void){
       cin.tie(0);
    ios::sync_with_stdio(false);

    long long n, a[2 * 100000 + 10], sum = 0, need, dp[2 * 100000 + 10][15];

    cin >> n;
    assert(n <= 2 * 100000);
    assert(n >= 1);
    for(int i = 0; i < n; i++){
        cin >> a[i];
        assert(a[i] <= 1000000000);
        assert(a[i] >= 1);
        a[i] %= 10;
        sum += a[i];
    }

    if(sum % 10 == 0)cout << n << "\n";
    else{
        //assert(sum % 10 == 0);
        need = sum % 10;

        for(int i = 0; i < n + 5; i++){
            for(int j = 0; j < 13; j++){
                dp[i][j] = LINF;
            }
        }

        dp[0][0] = 0;
        if(a[0] != 0){
        dp[0][a[0]] = 1;
        }
        for(int i = 1; i < n; i++){
            for(int j = 0; j < 10; j++){
                dp[i][(j + a[i]) % 10] = min(dp[i - 1][(j + a[i]) % 10], dp[i - 1][j] + 1);
            }
        }

        cout << n - dp[n - 1][need] << "\n";
    }
    return 0;
}