#include <iostream>

#include <vector>

#include <list>

using namespace std;

int N;

int board[500][500];

int dp[500][500];

bool visited[500][500];

int ans = 0;

int max(int a, int b) {

if (a > b) return a;

return b;

}

int dfs(int i, int j) {

if (dp[i][j]) return dp[i][j];

dp[i][j] = 1;

if (i > 0 && board[i - 1][j] > board[i][j]) {

dp[i][j] = max(dp[i][j], dfs(i - 1, j) + 1);

}

if (j > 0 && board[i][j - 1] > board[i][j]) {

dp[i][j] = max(dp[i][j], dfs(i, j - 1) + 1);

}

if (i<N - 1 && board[i + 1][j]>board[i][j]) {

dp[i][j] = max(dp[i][j], dfs(i + 1, j) + 1);

}

if (j<N - 1 && board[i][j + 1]>board[i][j]) {

dp[i][j] = max(dp[i][j], dfs(i, j + 1) + 1);

}

return dp[i][j];

}

int main()

{

cin >> N;

int i, j;

for (i = 0; i < N; i++) {

for (j = 0; j < N; j++) {

cin >> board[i][j];

}

}

for (i = 0; i < N; i++) {

for (j = 0; j < N; j++) {

ans = max(ans, dfs(i, j));

}

}

cout << ans;

}