#include <bits/stdc++.h>

using namespace std;
ifstream fin("inundatii.in");
ofstream fout("inundatii.out");
const int NMAX = 50010;
int n;
int X[NMAX], Y[NMAX], Z[NMAX];
int main()
{
    fin>>n;
    for(int i = 0; i<n; i++)
        fin>>X[n-i-1]>>Y[n-i-1]>>Z[n-i-1];
    int x=0,y=0,z=0;
    int xMin = X[0], yMin =Y[0], zMin = Z[0];
    for(int i = 1; i<n; i++)
    {
        x+=abs(X[i]-(xMin-1));
        xMin--;
        y+=abs(Y[i]-(yMin-1));
        yMin--;
        z+=abs(Z[i]-(zMin-1));
        zMin--;
    }
    fout<<x+y+z;
    return 0;
}