import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
public static int sumColumn(int[][] square, int columnNumber) {
    int sum = 0 ;
    for (int i = 0; i < square.length; i++)
        sum = sum + square[columnNumber][i] ;
    return sum ; 
}

public static int sumRow(int[][] square, int rowNumber)
{
    int sum = 0 ;
    for (int i = 0; i < square[0].length; i++)
        sum = sum + square[i][rowNumber] ;
    return sum ;
}
    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner reader = new Scanner(System.in);
        int n =0;
        int[][] matrix = new int[3][3];//automatically initialized with '0'

        int row = 0; // start with first row
        int col = n/2; //middle element
        int num = 1;  // nu
        for(int i=0;i<3;i++){
         for(int j=0;j<3;j++){
             matrix[i][j]=reader.nextInt();
         }
        }
        /*
       for(int line=0 ; line < 3 ; line++){
                for(int columna = 0; columna < 3 ; columna ++){
                   //  System.out.printf("\t %d \t",matrix[line][columna]);
                }
                System.out.println();
            }
            */
        int isSame=0;
        int notSame=0;
        for(int i=0; i<3;i++){
            if(sumRow(matrix,i)==15 && sumColumn(matrix,i)==15){
                
        //   System.out.println(sumRow(matrix,i));   
        //    System.out.println(sumColumn(matrix,i));
            
        }else{
           notSame=sumRow(matrix,i);
       //     System.out.println(notSame);
        }
          // System.out.println( (3*(3^2+1)/2));
      
        }
        
         System.out.println((15-notSame));
    }
}