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. */
        int[][] s= new int[3][3];
        Scanner scan=new Scanner(System.in);
        
          int x=0;
        int q=0;
        int w=0;
        for(int i=0;i<3;i++)
            for(int j=0;j<3;j++)
            s[i][j]=scan.nextInt();
          
            for(int k=0;k<3;k++)
               {
             for(int l=0;l<3;l++)
                 {
                 x=s[k][l];
                 for (int m=0;m<3;m++)
                     {
                     for (int n=0;n<3;n++)
                         {
                         if (m==k && n==l)
                             {
                              continue;
                             }
                         else
                             {
                             if(s[m][n]==x)
                                 {
                                  q=m;
                                  w=n;
                                  break;
                                 }
                              }
                        
                         }
                     }
                 }
             } 
        
        int count=0;
        int z;
        for (z=1;z<=9;z++)
            {
             count=0;
              for (int v=0;v<3;v++)
                  {
                     for (int c=0;c<3;c++)
                         {
                           if (s[v][c]==z)
                               {
                                 count++;
                               }
                         }
                  }
               if (count>0)
                   {
                    continue;
                   }
               else
                   {
                    break;
                   } 
            }
           System.out.print(z-x);
            
    }
}