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

public class Solution {

    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 scan = new Scanner(System.in);
        int[][] matrix = new int[3][3];
        int test;
        for(int i=0; i<3; i++){
            for(int j=0; j<3; j++){
                matrix[i][j] = scan.nextInt();
            }
        }
        int sumA = matrix[0][0] + matrix[0][1] + matrix[0][2];
        int sumB = matrix[1][0] + matrix[1][1] + matrix[1][2];
        int sumC = matrix[2][0] + matrix[2][1] + matrix[2][2];
        
        int sumD = matrix[0][0] + matrix[1][0] + matrix[2][0]; 
        int sumE = matrix[0][1] + matrix[1][1] + matrix[2][1];
        int sumF = matrix[0][2] + matrix[1][2] + matrix[2][2];
        
        int sumG = matrix[0][0] + matrix[1][1] + matrix[2][2];
        int sumH = matrix[0][2] + matrix[1][1] + matrix[2][0];
        
        if(sumA == sumB){
            if(sumD == sumE){
                if(sumD>sumF) test = 1;
                else test = -1;
                matrix[2][2] = matrix[2][2] + sumD - (sumF * test);
                System.out.println(sumD - (sumF * test));
            }
            if(sumD == sumF){
                if(sumD>sumE) test = 1;
                else test = -1;
                matrix[2][1] = matrix[2][1] + sumD - (sumE * test);
                System.out.println(sumD - (sumE * test));
            }
            if(sumE == sumF){
                if(sumE>sumF) test = 1;
                else test = -1;
                matrix[2][0] = matrix[2][0] + sumE - (sumF * test);
                System.out.println(sumE - (sumF * test));
            }
        }
        if(sumA == sumC){
            if(sumD == sumE){
                if(sumD>sumF) test = 1;
                else test = -1;
                matrix[1][2] = matrix[1][2] + sumD - (sumF * test);
                System.out.println(sumD - (sumF * test));
            }
            if(sumD == sumF){
                if(sumD>sumE) test = 1;
                else test = -1;
                matrix[1][1] = matrix[1][1] + sumD - (sumE * test);
                System.out.println(sumD - (sumE * test));
            }
            if(sumE == sumF){
                if(sumE>sumF) test = 1;
                else test = -1;
                matrix[1][0] = matrix[1][0] + sumE - (sumF * test);
                System.out.println(sumE - (sumF * test));
            }
        }
        if(sumB == sumC){
            if(sumD == sumE){
                if(sumD>sumF) test = 1;
                else test = -1;
                matrix[0][2] = matrix[0][2] + sumD - (sumF * test);
                System.out.println(sumD - (sumF * test));
            }
            if(sumD == sumF){
                if(sumD>sumE) test = 1;
                else test = -1;
                matrix[0][1] = matrix[0][1] + sumD - (sumE * test);
                System.out.println(sumD - (sumE * test));
            }
            if(sumE == sumF){
                if(sumE>sumF) test = 1;
                else test = -1;
                matrix[0][0] = matrix[0][0] + sumE - (sumF * test);
                System.out.println(sumE - (sumF * test));
            }
        }
    }
}