#include "sequence.h"
#include <bits/stdc++.h>
using namespace std;
#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0);
#define iter(a) a.begin(), a.end()
#define pb(a) emplace_back(a)
#define mp(a, b) make_pair(a, b)
#define ff first
#define ss second
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define SZ(a) int(a.size())
#ifdef LOCAL
void debug(){cerr << "\n";}
template<class T, class ... U> void debug(T a, U ... b){cerr << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
while (l != r) cerr << *l << " ", l++;
cerr << "\n";
}
#else
#define debug(...) void()
#define pary(...) void()
#endif
typedef long long ll;
typedef long double ld;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const ll MOD = 1000000007;
const ll MAX = 2147483647;
template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
return o << '(' << p.ff << ',' << p.ss << ')';
}
ll ifloor(ll a, ll b){
if(b < 0) a *= -1, b *= -1;
if(a < 0) return (a - b + 1) / b;
else return a / b;
}
ll iceil(ll a, ll b){
if(b < 0) a *= -1, b *= -1;
if(a > 0) return (a + b - 1) / b;
else return a / b;
}
#define lc 2 * id
#define rc 2 * id + 1
int n;
int sequence(int N, vector<int> A){
n = N;
vector<vector<int>> pos(n + 1);
for(int i = 0; i < n; i++){
pos[A[i]].pb(i);
}
int ans = 0;
for(int v = 1; v <= n; v++){
vector<int> sum(n);
{
int now = 0;
for(int j = 0; j < n; j++){
if(A[j] < v) now--;
else if(A[j] > v) now++;
sum[j] = now;
}
}
vector<pair<pii, int>> ev;
int lst = -1;
for(int i = 0; i < SZ(pos[v]); i++){
int j = pos[v][i];
int nxt = i + 1 == SZ(pos[v]) ? n : pos[v][i + 1];
{
int mn = sum[j], mx = sum[j];
for(int t = lst + 1; t <= j; t++){
mn = min(mn, sum[t]);
mx = max(mx, sum[t]);
}
int x = i - mx, y = i + mn;
ev.pb(mp(mp(x, y), i));
}
{
int mn = sum[j], mx = sum[j];
for(int t = j; t < nxt; t++){
mn = min(mn, sum[t]);
mx = max(mx, sum[t]);
}
int x = i - mn + 1, y = i + mx + 1;
for(auto [c, id] : ev){
if(c.ff <= x && c.ss <= y){
ans = max(ans, i - id + 1);
}
}
}
lst = j;
}
}
return ans;
}
