#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,M;
int A[16][16];
int B[16][16];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M;
	FOR(y,N) FOR(x,N) cin>>A[y][x];
	
	int mi=1<<30;
	int mask;
	FOR(mask,(1<<(N+2))) {
		if(N+__builtin_popcount(mask)<M) continue;
		int sum=0;
		FOR(x,N) FOR(y,N) B[y][x]=A[y][x];
		FOR(y,N) if(mask&(1<<y)) {
			FOR(x,N) sum+=B[y][x], B[y][x]=0;
		}
		if(mask&(1<<N)) {
			FOR(y,N) sum+=B[y][y], B[y][y]=0;
		}
		if(mask&(1<<(N+1))) {
			FOR(y,N) sum+=B[y][N-1-y], B[y][N-1-y]=0;
		}
		vector<int> V;
		FOR(x,N) {
			int s=0;
			FOR(y,N) s+=B[y][x];
			V.push_back(s);
		}
		sort(ALL(V));
		FOR(i,M-__builtin_popcount(mask)) sum+=V[i];
		mi=min(mi,sum);
	}
	cout<<mi<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}