#include <cstdio>

using namespace std;

const int MAX_N = 50000;

long long x[1 + MAX_N];
long long y[1 + MAX_N];
long long z[1 + MAX_N];

int main() {
  freopen("inundatii.in", "r", stdin);
  freopen("inundatii.out", "w", stdout);

  int n;

  scanf("%d", &n);
  for (int i = 1; i <= n; i++)
    scanf("%lld%lld%lld", &x[i], &y[i], &z[i]);

  long long ans;

  ans = 0;
  for (int i = 2; i <= n; i++) {
    ans += (x[i - 1] + 1 - x[i]);
    x[i] = x[i - 1] + 1;

    ans += (y[i - 1] + 1 - y[i]);
    y[i] = y[i - 1] + 1;

    ans += (z[i - 1] + 1 - z[i]);
    z[i] = z[i - 1] + 1;
  }

  printf("%lld\n", ans);
  return 0;
}