#include <bits/stdc++.h>
using namespace std;
int sequence(int n, vector<int> a) {
int l_max[n], l_min[n], r_max[n], r_min[n];
for (int i = 0; i < n; i++) {
l_max[i] = l_min[i] = r_max[i] = r_min[i] = i;
int c1 = 0, c2 = 0;
int Lmax = 0, Lmin = 0, Rmax = 0, Rmin = 0;
for (int j = i - 1; j >= 0; j--) {
if (a[j] == a[i]) break;
c1 += (a[j] < a[i]), c2 += (a[j] > a[i]);
if (c1 - c2 > Lmax) Lmax = c1 - c2, l_max[i] = j;
if (c1 - c2 < Lmin) Lmin = c1 - c2, l_min[i] = j;
}
int c3 = 0, c4 = 0;
for (int j = i + 1; j < n; j++) {
if (a[j] == a[i]) break;
c3 += (a[j] < a[i]), c4 += (a[j] > a[i]);
if (c3 - c4 > Rmax) Rmax = c3 - c4, r_max[i] = j;
if (c3 - c4 < Rmin) Rmin = c3 - c4, r_min[i] = j;
}
}
vector<int> pos[n + 1];
for (int i = 0; i < n; i++) pos[a[i]].emplace_back(i);
int res = 0;
for (int val = 1; val <= n; val++) {
for (int L = 0; L < n; L++) {
int c1 = 0, c2 = 0;
for (int R = L; R < n; R++) {
c1 += (a[R] < val), c2 += (a[R] > val);
if (abs(c1 - c2) <= (R - L + 1) - (c1 + c2) && (R - L + 1) > c1 + c2) {
res = max(res, R - L + 1 - c1 - c2);
}
}
}
}
for (int m = n; m >= 1; m--) {
for (int val = 1; val <= n; val++) {
for (int ind = 0; ind + m - 1 < (int) pos[val].size(); ind++) {
int LL = pos[val][ind], RR = pos[val][ind + m - 1], L, R;
for (int t1 = 0; t1 < 3; t1++) {
if (t1 == 0) L = LL;
else if (t1 == 1) L = l_max[LL];
else L = l_min[LL];
for (int t2 = 0; t2 < 3; t2++) {
if (t2 == 0) R = RR;
else if (t2 == 1) R = r_max[RR];
else R = r_min[RR];
int c1 = 0, c2 = 0;
for (int i = L; i <= R; i++) c1 += (a[i] < val), c2 += (a[i] > val);
if (abs(c1 - c2) <= m) {
if(m > res) exit(-1);
return m;
}
}
}
}
}
}
}
//int main() {
// ios_base::sync_with_stdio(false);
// cin.tie(nullptr), cout.tie(nullptr);
// int N;
// cin >> N;
// vector<int> A(N);
// for (int i = 0; i < N; i++) cin >> A[i];
// cout << sequence(N, A);
// return 0;
//}
