#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstring>
#include <deque>
#include <forward_list>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;
typedef long long ll;
typedef pair<int, int> P;
typedef bitset<16> BS;

const ll MOD = 1E+09 + 7;
const ll INF = 1E18;
const int MAX_N = 2E+05;

int N;

int A[MAX_N + 1], dp[MAX_N + 1][10];

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

    cin >> N;

    for (int i = 1; i <= N; i++) {
        cin >> A[i];
    }

    for (int j = 0; j < 10; j++) {
        dp[0][j] = -1E06;
    }
    dp[0][0] = 0;

    for (int i = 1; i <= N; i++) {
        //int r = A[i] % 10;
        for (int j = 0; j <= 9; j++) {
            dp[i][(j + A[i]) % 10] = max(dp[i - 1][(j + A[i]) % 10], dp[i - 1][j] + 1);
            //cout << "i = " << i << ", j = " << j << ", dp = " << dp[i][(j + A[i]) % 10] << "\n";
        }
    }

    /*
    for (int i = 1; i <= N; i++) {
        for (int j = 0; j < 10; j++) {
            cout << "i = " << i << ", j = " << j << ", dp = " << dp[i][j] << "\n";
        }
    }
    */

    cout << dp[N][0] << "\n";

    return 0;
}