#include <bits/stdc++.h>
static const int MAXN = 1004;
static const int RG = 8;
template <typename T>
inline void upd_max(T &var, const T val) {
  if (var < val) var = val;
}
int n, a[MAXN];
std::vector<int> occ[RG];
int occ_next[RG][MAXN];
int p[RG], xt_mask, base_len;
inline bool check() {
  int ptr = 0;
  for (int i = 0; i < RG; ++i) {
    int u = p[i];
    int this_len = base_len + ((xt_mask >> u) & 1);
    if (this_len <= 0) continue;
    ptr = occ_next[u][ptr];
    if ((ptr += (this_len - 1)) >= (int)occ[u].size()) return false;
    ptr = occ[u][ptr] + 1;
  }
  return true;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d", &a[i]);
    --a[i];
    occ[a[i]].push_back(i);
  }
  for (int i = 0; i < RG; ++i) {
    int last = 0;
    for (int j = 0; j < (int)occ[i].size(); ++j)
      for (; last <= occ[i][j]; ++last) occ_next[i][last] = j;
    for (; last < MAXN; ++last) occ_next[i][last] = (int)occ[i].size();
  }
  for (int i = 0; i < RG; ++i) p[i] = i;
  int ans = 0;
  do {
    for (xt_mask = 0; xt_mask < (1 << RG); ++xt_mask) {
      int lo = -1, hi = MAXN / RG + 10;
      while (lo < hi - 1) {
        base_len = (lo + hi) >> 1;
        if (check())
          lo = base_len;
        else
          hi = base_len;
        if (ans >= __builtin_popcount(xt_mask) + hi * 8) break;
      }
      if (lo >= 0) upd_max(ans, __builtin_popcount(xt_mask) + lo * 8);
    }
  } while (std::next_permutation(p, p + RG));
  printf("%d\n", ans);
  return 0;
}
