#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;
#ifndef WAIMAI
#include "soccer.h"
#else
#include "grader.cpp"
#endif
#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif
#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second
const int SIZE = 505;
int n, ans;
int a[SIZE][SIZE], L[SIZE][SIZE][SIZE], R[SIZE][SIZE][SIZE], dp[SIZE][SIZE][SIZE];
int biggest_stadium(int N, vector<vector<int>> F) {
n = N;
FOR (i, 1, n) FOR (j, 1, n) a[i][j] = F[i - 1][j - 1];
FOR (i, 1, n) {
FOR (j, 1, n) if (a[i][j] == 0) L[i][i][j] = (j > 1 && a[i][j - 1] == 0 ? L[i][i][j - 1] : j);
for (int j = n; j >= 1; j--) if (a[i][j] == 0) R[i][i][j] = (j < n && a[i][j + 1] == 0 ? R[i][i][j + 1] : j);
}
FOR (u, 1, n) FOR (d, u + 1, n) FOR (j, 1, n) {
if (L[u][d - 1][j] && L[d][d][j]) L[u][d][j] = max(L[u][d - 1][j], L[d][d][j]);
if (R[u][d - 1][j] && R[d][d][j]) R[u][d][j] = min(R[u][d - 1][j], R[d][d][j]);
}
FOR (i, 1, n) FOR (j, 1, n) if (L[i][i][j]) dp[i][i][j] = R[i][i][j] - L[i][i][j] + 1;
FOR (d, 1, n) for (int u = d - 1; u >= 1; u--) FOR (j, 1, n) if (L[u][d][j]) {
dp[u][d][j] = max(dp[u][d - 1][j], dp[u + 1][d][j]) + R[u][d][j] - L[u][d][j] + 1;
ans = max(ans, dp[u][d][j]);
}
return ans;
}
/*
in1
5
0 0 0 0 0
1 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 1 0 0
out1
20
*/
