#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
const int N = 8;
int n;
int total = (1 << N);
vector<vector<int> > dp;
vector<vector<int> > position(N);
vector<vector<int> > precalc;
int calcDP(int pos, int mask, int len) {
  if (pos == n) {
    return !mask ? 0 : -INF;
  }
  if (dp[pos][mask] != -1) {
    return dp[pos][mask];
  }
  dp[pos][mask] = !mask ? 0 : -INF;
  if (pos == n) {
    return dp[pos][mask];
  }
  for (int i = 0; i < N; i++) {
    if (mask & (1 << i)) {
      int idx = precalc[i][pos];
      if (idx + len < position[i].size()) {
        dp[pos][mask] =
            max(dp[pos][mask],
                1 + calcDP(position[i][idx + len] + 1, mask ^ (1 << i), len));
      }
      if (len) {
        if (idx + len - 1 < position[i].size()) {
          dp[pos][mask] =
              max(dp[pos][mask],
                  calcDP(position[i][idx + len - 1] + 1, mask ^ (1 << i), len));
        }
      } else {
        dp[pos][mask] = max(dp[pos][mask], calcDP(pos, mask ^ (1 << i), len));
      }
    }
  }
  return dp[pos][mask];
}
void solve() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int item;
    cin >> item;
    item--;
    position[item].push_back(i);
  }
  precalc.resize(N, vector<int>(n));
  for (int i = 0; i < N; i++) {
    int ptr = 0;
    for (int j = 0; j < position[i].size(); j++) {
      while (ptr <= position[i][j]) {
        precalc[i][ptr] = j;
        ptr++;
      }
    }
    while (ptr < n) {
      precalc[i][ptr] = position[i].size();
      ptr++;
    }
  }
  int lf = -1;
  int rg = n / N + 1;
  while (rg - lf > 1) {
    int middle = (lf + rg) / 2;
    dp.clear();
    dp.resize(n, vector<int>(total, -1));
    if (calcDP(0, total - 1, middle) >= 0) {
      lf = middle;
    } else {
      rg = middle;
    }
  }
  dp.clear();
  dp.resize(n, vector<int>(total, -1));
  cout << lf * N + calcDP(0, total - 1, lf) << endl;
}
int main() {
  srand(time(NULL));
  solve();
  return 0;
}
