#include <bits/stdc++.h>
using namespace std;

template<typename T, typename U> void cmax(T &a, U b) { if (a < b) a = b; }
template<typename T, typename U> void cmin(T &a, U b) { if (a > b) a = b; }

signed main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);

  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++) cin >> A.at(i);

  long acc = accumulate(A.begin(), A.end(), 0L);
  int X = acc % 10;

  vector<int> DP(10, INT_MAX);
  DP.at(0) = 0;
  for (auto a : A) {
    auto C = DP;
    for (int i = 0; i < 10; i++) {
      if (DP.at(i) == INT_MAX) continue;
      int next = (i + a) % 10;
      cmin(C.at(next), DP.at(i) + 1);
    }
    DP = C;
  }
  cout << N - DP.at(X) << "\n";
}