#include <bits/stdc++.h>
using namespace std;
using int128  = __int128_t;
using int64   = long long;
using int32   = int;
using uint128 = __uint128_t;
using uint64  = unsigned long long;
using uint32  = unsigned int;

#define ALL(obj) (obj).begin(),(obj).end()
template<class T> using priority_queue_reverse = priority_queue<T,vector<T>,greater<T>>;

constexpr int64 MOD = 1'000'000'000LL + 7; //'
constexpr int64 MOD2 = 998244353;
constexpr int64 HIGHINF = 1'000'000'000'000'000'000LL;
constexpr int64 LOWINF = 1'000'000'000'000'000LL; //'
constexpr long double PI = 3.1415926535897932384626433L;

template <class T> vector<T> multivector(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto multivector(size_t N,T... t){return vector<decltype(multivector(t...))>(N,multivector(t...));}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const deque<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max(a,b);}
template <class T> void chmin(T& a, const T b){a=min(a,b);}
vector<string> split(const string &str, const char delemiter) {vector<string> res;stringstream ss(str);string buffer; while( getline(ss, buffer, delemiter) ) res.push_back(buffer); return res;}
inline constexpr int msb(int x) {return x?31-__builtin_clz(x):-1;}
inline constexpr int64 ceil_div(const int64 a,const int64 b) {return (a+(b-1))/b;}// return ceil(a/b)
void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;}

int N,M; 
auto A = multivector(16,16,0);

int f_y(int i) {
    int sum = 0;
    for(int j=0;j<N;++j) sum += A[i][j];
    return sum;
}

int f_x(int j) {
    int sum = 0;
    for(int i=0;i<N;++i) sum += A[i][j];
    return sum;
}

int f_z(int k) {
    int sum = 0;
    if(k==0) for(int i=0;i<N;++i) sum += A[i][i];
    if(k==1) for(int i=0;i<N;++i) sum += A[i][N-1-i];
    return sum;
}

/**
 * @url 
 * @est
 */ 
int main() {
    cin.tie(0);ios::sync_with_stdio(false);
    cin >> N >> M;
    for(int i=0;i<N;++i) for(int j=0;j<N;++j) cin >> A[i][j];
    vector<int> used(2*N+2,0);
    int ans = 0;
    for(int n=0;n<M;++n) {
        vector<pair<int,int>> vp;
        for(int i=0;i<N;++i) if(!used[i]) {
            vp.push_back({f_y(i),i});
        }
        for(int i=0;i<N;++i) if(!used[i+N]) {
            vp.push_back({f_x(i),i+N});
        }
        if(!used[2*N+0]) {
            vp.push_back({f_z(0),2*N+0});
        }
        if(!used[2*N+1]) {
            vp.push_back({f_z(1),2*N+1});
        }
        sort(ALL(vp));
        ans += vp.front().first;
        int idx = vp.front().second;
        used[idx] = 1;
        if(idx < N) {
            for(int j=0;j<N;++j) A[idx][j]=0;
        }
        else if(idx < 2*N) {
            idx -= N;
            for(int i=0;i<N;++i) A[i][idx]=0;
        }
        else if(idx == 2*N) {
            for(int i=0;i<N;++i) A[i][i]=0;
        }
        else if(idx == 2*N+1) {
            for(int i=0;i<N;++i) A[i][N-1-i]=0;
        }
    }
    cout << ans << endl;
    return 0;
}