#include <bits/stdc++.h>
using namespace std;
const int maxn = 1050;
int dp[maxn][9], nxt[maxn][9][maxn], a[maxn], n, cnt[9];
inline int ask(int k) { return (1 << (k - 1)); }
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
  for (int i = 1; i <= n; ++i) {
    for (int j = 1; j <= 8; ++j) cnt[j] = 0;
    for (int j = 1; j <= 8; ++j)
      for (int k = 1; k <= n; ++k) nxt[i][j][k] = 1e9;
    for (int j = i; j <= n; ++j) nxt[i][a[j]][++cnt[a[j]]] = j;
  }
  int ans = 0;
  for (int num = 0; num * 8 <= n; ++num) {
    for (int i = 0; i < 256; ++i)
      for (int k = 0; k <= 8; ++k) dp[i][k] = 1e9;
    dp[0][0] = 1;
    for (int i = 0; i < 256; ++i)
      for (int j = 0; j <= 8; ++j)
        for (int k = 1; k <= 8; ++k) {
          if (dp[i][j] > n || ask(k) & i) continue;
          dp[i ^ ask(k)][j] = min(dp[i ^ ask(k)][j], nxt[dp[i][j]][k][num] + 1);
          dp[i ^ ask(k)][j + 1] =
              min(dp[i ^ ask(k)][j + 1], nxt[dp[i][j]][k][num + 1] + 1);
        }
    for (int i = 0; i <= 8; ++i)
      if (dp[255][i] <= n + 1) ans = max(ans, 8 * num + i);
  }
  cout << ans << endl;
  return 0;
}
