#include <bits/stdc++.h>
#define ll long long
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()
#define fr first
#define se second
#define pb push_back
#define mp make_pair
using namespace std;
vector<ll>seg,I,D;
ll pot, tam;
void update(ll nod, ll x)
{
seg[nod]+=x;
nod/=2;
while(nod>0)
{
seg[nod]+=x;
nod/=2;
}
}
ll calc(ll x, ll nod, ll act)
{
if(nod>=pot)
return nod-pot;
if(seg[nod*2]+act>=x)
return calc(x,nod*2,act);
return calc(x,nod*2+1,seg[nod*2]+act);
}
int sequence(int N, std::vector<int> A)
{
seg.resize(0);
I.resize(0);
D.resize(0);
pot=1;
ll i, j;
ll ma=0;
while(pot<(N+1))
pot*=2;
seg.resize(pot*2,0);
I.resize(pot*2);
D.resize(pot*2);
for (i = 0; i < sz(A); i++)
{
map<ll,ll>ap;
tam=0;
for (j = i; j < sz(A); j++)
{
update(A[j]+pot,1);
ap[A[j]]++;
ll a=calc((tam/2)+1,1,0);
ll b=calc((tam+1)/2+1,1,0);
ma=max(ma,ap[a]);
ma=max(ma,ap[b]);
tam++;
}
for(j=i; j<sz(A); j++)
update(A[j]+pot,-1);
}
return ma;
}
