#include<stdio.h>
#include<stdlib.h>
long n,i,a[50005],b[50005],c[50005],x,s;
int main()
{
 freopen("inundatii.in","r",stdin);
 freopen("inundatii.out","w",stdout);
 scanf("%ld",&n);
 for(i=1;i<=n;i++)
    {scanf("%ld%ld%ld",&a[i],&b[i],&c[i]);
     a[i]-=i;
     b[i]-=i;
     c[i]-=i;}
 for(i=1;i<=n;++i)
    {x=a[n/2+n%2]+i;
     s+=(labs(x-a[i]-i));
     x=b[n/2+n%2]+i;
     s+=(labs(x-b[i]-i));
     x=c[n/2+n%2]+i;
     s+=(labs(x-c[i]-i));}
 printf("%ld\n",s);
 return 0;
}