#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y));
#define chmax(x,y) x = max((x),(y));
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;

int a[20][20];

int main(){
    int n,m;
    cin >> n >> m;
    rep(i,n)rep(j,n) cin >> a[i][j];
    ll ans = LINF;
    rep(mask,4){
        ll res = 0;
        int t = 0;
        vector<vector<int>> maze(n,vector<int>(n,0));
        if(mask&1){
            ++t;
            rep(i,n){
                maze[i][i] = 1;
                res += a[i][i];
            }
        }
        if(mask>>1&1){
            ++t;
            rep(i,n){
                maze[i][n-i-1] = 1;
                res += a[i][n-i-1];
            }
        }
        for(int bit=0;bit<(1<<n);bit++){
            int pop = __builtin_popcount(bit) + t;
            ll ret = 0;
            rep(i,n){
                if(bit>>i&1){
                    rep(j,n){
                        if(maze[i][j]==0) ret += a[i][j];
                    }
                }
            }
            int num = m - pop;
            vector<int> b(n,0);
            rep(i,n){
                rep(j,n){
                    if(bit>>j&1) continue;
                    if(maze[j][i]==1) continue;
                    b[i] += a[j][i];
                }
            }
            sort(b.begin(),b.end());
            rep(i,num) ret += b[i];
            chmin(ans,res+ret);
        } 
    }
    cout << ans << endl;
    return 0;
}