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


int main()
{
    int x[3][3],missing,extra=0,extraN,missingN,num;
    for(int i=0;i<3;i++){
        for(int j=0;j<3;j++){
            cin>>x[i][j];
        }
    }
    int y[9]={1,2,3,4,5,6,7,8,9},k=1;
    for(int k=0;k<9;k++)
    {
        extra=0;
        missing=0;
        for(int i=0;i<3;i++)
        {
            for(int j=0;j<3;j++)
            {
                if(x[i][j] == y[k])
                extra++;
             }
        }
        if(extra==2)
            extraN=k;
        if(extra==0)
            missingN=k;
}
    if(extraN>missingN){
        num=extraN-missingN;
    }
    else
        num=missingN-extraN;
    
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    cout<<num;
    return 0;
}