#include <bits/stdc++.h>

using namespace std;

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

int n, x[50002], z[50002], y[50002];

long long ans;

void solve (int v[], int n) {
  for (int i = 1; i <= n; i++)
    v[i] -= i;
  int med = v[n / 2 + 1];
  for (int i = 1; i <= n; i++)
    ans += abs(med - v[i]);
}
int main()
{
  fin >> n;
  for (int i = 1; i <= n; i++) {
    fin >> x[i] >> y[i] >> z[i];
  }
  solve(x, n);
  solve(y, n);
  solve(z, n);
  fout << ans;
  return 0;
}