#include <stdio.h>
using namespace std;
int main()
{
 freopen("inundatii.in","r",stdin);
 freopen("inundatii.out","w",stdout);
 long n,i,x[50000],y[50000],z[50000];
 scanf("%ld\n",&n);
 for (i=0;i<n;i++)
  scanf("%ld %ld %ld\n",&x[i],&y[i],&z[i]);
 long long s=0;
 for (i=1;i<n;i++)
 {
  if (x[i]<=x[i-1])
  {
   s+=x[i-1]-x[i]+1;
   x[i]=x[i-1]+1;
  }
  if (y[i]<=y[i-1])
  {
   s+=y[i-1]-y[i]+1;
   y[i]=y[i-1]+1;
  }
  if (z[i]<=z[i-1])
  {
   s+=z[i-1]-z[i]+1;
   z[i]=z[i-1]+1;
  }
 }
 printf("%lld\n",s);
 return 0;
}