import java.util.*;
public class B_17829 {
    public static int[][] board;

    public static int getSecondValue(int ...values){
        int secondValue = Integer.MIN_VALUE;
        int maxValue = Integer.MIN_VALUE;
        for(int val : values){
            if(maxValue <= val){
                secondValue = maxValue;
                maxValue = val;
            }
            if(val < maxValue && secondValue < val ) secondValue = val;
        }
        return secondValue;
    }

    public static int partition(int row, int col, int size){
        if(size == 1) return board[row][col];
        // 4개로 나누기
        int nSize = size/2;
        return getSecondValue(partition(row, col, nSize),partition(row+nSize, col, nSize),partition(row, col+nSize, nSize),partition(row+nSize, col+nSize, nSize));
    }
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        board = new int[N][N];
        for(int i=0; i<N; i++){
            for(int j=0; j<N; j++){
                board[i][j] = sc.nextInt();
            }
        }
        System.out.println(partition(0,0,N));
    }
}