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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    int a,b,c,d,e,f,g,h,i;
    std::cin >>a>>b>>c;
    std::cin >>d>>e>>f;
    std::cin >>g>>h>>i;
   // int z[] = {a+b+c,d+e+f,g+h+i,a+d+g,b+e+h,c+f+i,a+e+i,c+e+g};
   // int tot = 15;
    int diff=0;//,s,t;//mindiff=100;
  /*  for(int j = 0; j<8 ; j++ )
{
        if(z[j]!=tot)
            {
            diff=abs(tot-z[j]);
        //if(mindiff>diff)
            //mindiff=diff;
        }
    /*if(z[j] != z[j+1]){
        if(z[j] > z[j+1]){diff = z[j] - z[j+1];}
        else {diff = z[j+1] - z[j];}
        break;*/
  /*  if(e!=5)
        diff=diff+abs(e-5);
    s=a+c+g+i;
    if(s!=20)
        diff=diff+abs(s-20);
    t=b+d+f+h;
    if(t!=20)
        diff=diff+abs(t-20);
    //}*/
    diff=abs((a+b+c+d+e+f+g+h+i)-45);
    std::cout<< diff;
    }