/*
 *   Copyright (c) 2024 Emon Thakur
 *   All rights reserved.
 */
#include<bits/stdc++.h>
using namespace std;

int degree[2003],two=0;

bool valid(int u,int v,int lim)
{
    if(degree[u]==2 || degree[v]==2) return false;
    int c =0;
    if(degree[u]==1) ++c;
    if(degree[v]==1) ++c;
    if(two + c > lim) return false;
    two += c;
    degree[u]++;
    degree[v]++;
    return true;
}

int main()
{
    int n,k; cin >> n >> k;
    int a[n][k];
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<k;j++) cin >> a[i][j];
    }
    if(n==1)
    {
        cout<<0<<endl;
        return 0;
    }

    priority_queue<vector<int>>pq;
    for(int i=0;i<n;i++)
    {
        for(int j=i+1;j<n;j++)
        {
            int cost = 0;
            for(int m=0;m<k;m++) cost += abs(a[i][m]-a[j][m]);
            pq.push({cost,i,j});
        }
    }

    int need = n-2;
    vector<int> x = pq.top();
    long long ans = x[0];
    pq.pop();
    set<int> nodes;
    nodes.insert(x[1]);
    nodes.insert(x[2]);

    while(nodes.size() != n)
    {
        x = pq.top();
        pq.pop();
        nodes.insert(x[1]);
        nodes.insert(x[2]);
        if(valid(x[1],x[2],nodes.size()-2))
        {
            ans += x[0];
        }
        else
        {
            nodes.erase(nodes.find(x[1]));
            nodes.erase(nodes.find(x[2]));
        }
    }

    cout << ans << endl;
}