#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n;
    cin >> n;

    int sum = 0;
    vector<int> dp(10, n);
    dp[0] = 0;

    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        sum += a, sum %= 10;

        vector<int> after(10, n);
        for (int j = 0; j < 10; j++) {
            after[(j + a) % 10] = min(dp[(j + a) % 10], dp[j] + 1);
        }
        dp = after;
    }

    cout << n - dp[sum] << endl;
    return 0;
}