#include <fstream>

#define DIM 50010

using namespace std;

ifstream fin ("inundatii.in");
ofstream fout ("inundatii.out");

int n;

struct cladire{

    int x;
    int y;
    int z;

}v[DIM];

int main () {

    fin >> n;

    for (int i = 1; i <= n; i++)
        fin >> v[i].x >> v[i].y >> v[i].z;

    int sol = 0;

    int lastx, lasty, lastz;

    lastx = v[n].x;
    lasty = v[n].y;
    lastz = v[n].z;

    if (v[n].x < n){

        lastx = n;
        sol += n - v[n].x;

    }
    if (v[n].y < n){

        lasty = n;
        sol += n - v[n].y;

    }
    if (v[n].z < n){

        lastz = n;
        sol += n - v[n].z;

    }


    for (int i = n - 1; i >= 1; i--) {

        lastx--;
        lasty--;
        lastz--;

        sol += v[i].x - lastx;
        sol += v[i].y - lasty;
        sol += v[i].z - lastz;

    }

    fout << sol << "\n";

    return 0;

}

//Trust me, I'm the Doctor!
//Miriam e tare!