#pragma region include
#include <iostream>
#include <iomanip>
#include <stdio.h>

#include <sstream>
#include <algorithm>
#include <iterator>
#include <cmath>
#include <complex>

#include <string>
#include <cstring>
#include <vector>
#include <tuple>
#include <bitset>

#include <queue>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <fstream>
#include <random>
//#include <time.h>
#include <ctime>
#pragma endregion //#include
/////////
#define REP(i, x, n) for(int i = x; i < n; ++i)
#define rep(i,n) REP(i,0,n)
#define ALL(X) X.begin(), X.end()
/////////
#pragma region typedef
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
typedef std::pair<LL,LL> PLL;//
typedef std::pair<int,int> PII;//
#pragma endregion //typedef
////定数
const int INF = (int)1e9;
const LL MOD = (LL)1e9+7;
const LL LINF = (LL)4e18+20;
const LD PI = acos(-1.0);
const double EPS = 1e-9;
/////////
using namespace::std;

void solve(){
	int N,M;
	cin >> N >> M;
	--N;
	vector< vector<LL> > A(M,vector<LL>(M,0) );
	vector< vector< vector<LL> > >dp2(32,
			vector< vector<LL> >(M,
					vector<LL>(M,0)
			)
	);
	for(int r=0;r<M;++r){
		for(int c=0;c<M;++c){
			cin >> A[r][c];
		}
	}

	{
		for(int r=0;r<M;++r){
			for(int c=0;c<M;++c){
				dp2[0][r][c] = max(dp2[0][r][c],A[r][c]);
			}
		}
	}
	for(int i=1;i<32;++i){
		for(int A=0;A<M;++A){
			for(int B=0;B<M;++B){
				for(int C=0;C<M;++C){
					//A->B->C
					dp2[i][A][C] = max(dp2[i][A][C],dp2[i-1][A][B]+dp2[i-1][B][C] );
				}
			}
		}
	}
	
	vector< vector<LL> > ans(M,vector<LL>(M,-1));
	for(int i=0;i<M;++i){
		ans[i][i] = 0;
	}
	int bit = 0;
	while(N){
		if( N&1 ){
			vector< vector<LL> > next(M,vector<LL>(M,-1));
			for(int A=0;A<M;++A){
				for(int B=0;B<M;++B){
					if( ans[A][B] < 0 ) continue;
					for(int C=0;C<M;++C){
						next[A][C] = max(next[A][C],ans[A][B] + dp2[bit][B][C]);
					}
				}
			}
			ans = next;
		}
		N >>= 1;
		++bit;
	}

	LL AAA = 0;
	for(int r=0;r<M;++r){
		for(int c=0;c<M;++c){
			AAA = max(AAA,ans[r][c]);
		}
	}
	cout << AAA << endl;
}

#pragma region main
signed main(void){
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);
	std::cout << std::fixed;//小数を10進数表示
	cout << setprecision(16);//小数点以下の桁数を指定//coutとcerrで別	

	solve();
}
#pragma endregion //main()