#include <bits/stdc++.h>
using namespace std;

ifstream fin("acces.in");
ofstream fout("acces.out");

int n, a[1005][1005];
int b[1005][1005];
int dx[] = {0, 0, 1, -1};
int dy[] = {-1, 1, 0, 0};
queue < pair < int, int > > Q;
void Citire()
{
    int i, j;
    fin >> n;
    for(i = 1; i <= n; i++)
        for(j = 1; j <= n; j++)
        fin >> a[i][j];
    fin.close();
}
void Bordare()
{
    int i, j;
    for(i = 0; i <= n + 1; i++)
    {
        a[i][0] = a[i][n + 1] = 1000002;
        a[0][i] = a[n + 1][i] = 1000002;
    }
}
void Init()
{
    int i, j;
    for(i = 1; i <= n; i++)
        for(j = 1; j <= n; j++)
           b[i][j] = 1000000;
}
void Lee()
{
    int k, i, j, x, y;
    b[1][1] = a[1][1];
    Q.push({1, 1});
    while( !Q.empty())
    {
        i = Q.front().first;
        j = Q.front().second;
        Q.pop();
        for(k = 0; k < 4; k++)
        {
            x = i + dx[k];
            y = j + dy[k];
            if(b[x][y] > max(b[i][j], a[x][y]) && b[x][y] != 1000002)
            {
                b[x][y] = max(b[i][j], a[x][y]);
                Q.push({x, y});
            }
        }
    }
    fout << b[n][n] << "\n";
    fout.close();
}
int main()
{
    Citire();
    Bordare();
    Init();
    Lee();
    return 0;
}