#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;
#define bit(n,k) ((n>>k)&1)

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    int N,M; cin >> N >> M;
    vector<vector<int>> A(N, vector<int> (N));
    rep(i,N)rep(j,N) cin >> A[i][j];
    int ans = 1e9;
    rep(i,1<<(N+2)){
        auto B = A;
        int cost = 0;
        rep(j,N+2)if(bit(i,j)){
            if(j == N){
                rep(k,N){
                    cost += B[k][k];
                    B[k][k] = 0;
                }
            }else if(j == N + 1){
                rep(k,N){
                    cost += B[k][N-1-k];
                    B[k][N-1-k] = 0;
                }
            }else{
                rep(k,N){
                    cost += B[k][j];
                    B[k][j] = 0;
                }
            }
        }

        vector<int> v;
        rep(j,N){
            int tmp = 0;
            rep(k,N) tmp += B[j][k];
            v.emplace_back(tmp);
        }
        sort(v.begin(), v.end());
        rep(j,M-__builtin_popcount(i)) cost += v[j];
        ans = min(ans, cost);
    }
    cout << ans << '\n';
}