#include <bits/stdc++.h>
#define l long long
l x[50002],y[50002],z[50002],mx,my,mz,sol;std::ifstream fin("inundatii.in");std::ofstream fout("inundatii.out");int main(){int n,i;fin>>n;for(i=1;i<=n;++i) fin>>x[i]>>y[i]>>z[i],x[i]-=i,y[i]-=i,z[i]-=i;for(i=1;i<=n;++i) sol+=abs(x[i]-x[n/2+1])+abs(y[i]-y[n/2+1])+abs(z[i]-z[n/2+1]);fout<<sol<<"\n";return 0;}