#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

template <typename T>
struct bit{
    int n;
    vector<T> data;

    bit(int n_){
        n = 1;
        while(n < n_) n *= 2;
        data = vector<T>(n+1);
        for(int i = 0; i <= n; i++) data[i] = 0;
    }
    
    T sum(int i){
        T ret = 0;
        while(i > 0){
            ret += data[i];
            i -= i&-i;
        }
        return ret;
    }
    T all(){
        return sum(n);
    }

    void add(int i, T x){
        while(i <= n){
            data[i] += x;
            i += i&-i;
        }
    }
};

template<typename T>
class Compress{
    public:
    vector<T> data;
    int offset;
    Compress(vector<T> data_, int offset=0): offset(offset){
        set<T> st;
        for(T x: data_) st.insert(x);
        for(T x: st) data.push_back(x);
    };
    int operator[](T x) {
        auto p = lower_bound(data.begin(), data.end(), x);
        assert(x == *p);
        return offset+(p-data.begin());
	}
    T inv(int x){
        return data[x-offset];
    }
    int size(){
        return data.size();
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int m, k; cin >> m >> k;
    vector<int> a(m*k);
    vector<vector<int>> idx(m);

    for(int i = 0; i < m*k; i++) {
        cin >> a[i];
        idx[a[i]].push_back(i+1);
    }
    ll ans = 0;
    bit<ll> bt(k*m);
    for(int i = 0; i < k; i++){
        for(int j = 0; j < m; j++){
            ans += bt.all() - bt.sum(idx[j][i]);
            bt.add(idx[j][i], 1); 
        }
    }
    // debug_value(ans);
    ll tmp = ans;
    vector<bit<ll>> bts(k, bit<ll>(m));
    vector<vector<int>> idx_cp(k);
    for(int i = 0; i < k; i++){
        vector<int> v(m);
        for(int j = 0; j < m; j++){
            v[j] = idx[j][i];
        }
        auto cp = Compress<int>(v, 1);
        for(int j = 0; j < m; j++){
            idx_cp[i].push_back(cp[v[j]]);
        }
        for(int j = 0; j < m; j++){
            bts[i].add(idx_cp[i][j], 1);
        }
    }
    for(int j = 0; j < m; j++){
        for(int i = 0; i < k; i++){
            // jを一番うしろに持ってくる
            bts[i].add(idx_cp[i][j], -1);
            tmp -= bts[i].sum(idx_cp[i][j]);
            tmp += bts[i].all() - bts[i].sum(idx_cp[i][j]);
            bts[i].add(idx_cp[i][j], 1);
        }
        chmin(ans, tmp);
    }
    cout << ans << endl;
}