#include "soccer.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 30 + 7;
int a[N][N], pref[N][N], dp[N][N][N][N];
bool ok(int l, int x, int y) {
return pref[l][y] - pref[l][x - 1] == 0;
}
int biggest_stadium(int n, vector<vector<int>> f) {
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
a[i][j] = f[i - 1][j - 1];
pref[i][j] = pref[i][j - 1] + a[i][j];
}
}
for (int i = 1; i <= n; ++i) {
for (int l = 1; l <= n; ++l) {
for (int r = l; r <= n; ++r) {
dp[i][i][l][r] = -1e9;
if (ok(i, l, r)) dp[i][i][l][r] = r - l + 1;
}
}
}
for (int h = n; h >= 1; --h) {
for (int l = 1; l + h - 1 <= n; ++l) {
int r = l + h - 1;
for (int h2 = 1; h2 <= n; ++h2) {
for (int down = 1; down + h2 - 1 <= n; ++down) {
int up = down + h2 - 1;
for (int x = l; x <= r; ++x) {
for (int y = x; y <= r; ++y) {
if (ok(down - 1, x, y)) {
dp[down - 1][up][x][y] = max(dp[down - 1][up][x][y], dp[down][up][l][r] + y - x + 1);
}
if (ok(up + 1, x, y)) {
dp[down][up + 1][x][y] = max(dp[down][up + 1][x][y], dp[down][up][l][r] + y - x + 1);
}
}
}
}
}
}
}
int ans = 0;
for (int down = 1; down <= n; ++down) {
for (int up = down; up <= n; ++up) {
for (int l = 1; l <= n; ++l) {
for (int r = l; r <= n; ++r) {
ans = max(ans, dp[down][up][l][r]);
}
}
}
}
return ans;
}
