#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int a[3][3];
    int ans;
    for(int i = 0;i<3;i++)
        {
        for(int j = 0;j<3;j++)
            {
            cin>>a[i][j];
        }
    }
       for(int i=0;i<3;i++)
           {
           for(int j=0;j<1;j++)
               {
               if((a[i][j]+a[i][j+1]+a[i][j+2])!=15)
                   {
                   int temp = 15-(a[i][j]+a[i][j+1]+a[i][j+2]);
                  ans = a[i][j+2];
                 a[i][j+2]= temp+a[i][j+2];
                   ans = a[i][j+2]- ans;
               }
           }
       }
    
     //for(int i = 0;i<3;i++)
       // {
        //for(int j = 0;j<3;j++)
          //  {
           // cout<<a[i][j]<<" ";
       // } cout<<"\n";
   // }
    cout<<ans;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}