#include<stdio.h>
#define LMAX 50001

long long n,mat[LMAX][3],i,s,var;

int citire()
{scanf("%lld",&n);
 for(i=1;i<=n;i++)
 scanf("%lld %lld %lld",&mat[i][0],&mat[i][1],&mat[i][2]);}

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

 citire();

 if(n==1) printf("0\n");
 else
 {s+=(mat[1][0]-mat[2][0])+1;
  s+=(mat[1][1]-mat[2][1])+1;
  s+=(mat[1][2]-mat[2][2])+1;

  for(i=3;i<=n;i++)
  {var=mat[i-1][0]-mat[i][0]+1;
   s+=var; mat[i][0]+=var;

   var=mat[i-1][1]-mat[i][1]+1;
   s+=var; mat[i][1]+=var;

   var=mat[i-1][2]-mat[i][2]+1;
   s+=var; mat[i][2]+=var;}
      printf("%lld\n",s);}


}