#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <cmath>
#include <tuple>
#include <cstdio>
#include <bitset>
#include <sstream>
#include <iterator>
#include <numeric>
#include <map>
#include <cstring>
#include <set>
#include <functional>
#include <iomanip>

using namespace std;

#define DEBUG_ //!!$BDs=P;~$K%3%a%s%H%"%&%H(B!!
#ifdef DEBUG_
#define dump(x)  cerr << #x << " = " << (x) << endl;
#else
#define dump(x)  ;
#endif

#define equals(a,b) (fabs((a)-(b)) < EPS)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back

//#define int long long

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

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 (b<a) { a=b; return 1; } return 0; }

    template <typename T>
std::string printVector(const std::vector<T> &data)
{
    std::stringstream ss;
    std::ostream_iterator<T> out_it(ss, ", ");
    ss << "[";
    std::copy(data.begin(), data.end() - 1, out_it);
    ss << data.back() << "]";
    return ss.str();
}

template <typename T>
void print_array(const T &ary, int size){
    REP(i,size){
        cout << ary[i] << " ";
    }
    cout << endl;
}

const int mod = 1e9+7;
const LL LINF = 1001002003004005006ll;
const int INF = 1001001001;
const double EPS = (1e-10);

LL A[30][30];
LL dp[40][30][30];
LL ans[30][30];

// 写経 https://www.hamayanhamayan.com/entry/2017/10/07/010528

signed main(int argc, char const *argv[])
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(12);

    LL N,M; cin >> N >> M;
    REP(i,M) REP(j,M) cin >> A[i][j];
    REP(i,M) REP(j,M) dp[0][i][j] = A[i][j];
    FOR(i,1,40) REP(x,M) REP(y,M){
        REP(z,M){
            dp[i][x][y] = max(dp[i][x][y], dp[i-1][x][z] + dp[i-1][z][y]);
        }
    }
    N--;
    int d = 0;
    while(N){
        if(N%2){
            LL ans2[30][30];
            REP(x,M) REP(y,M) ans2[x][y] = 0;
            REP(x,M) REP(y,M){
                REP(z,M) ans2[x][y] = max(ans2[x][y], ans[x][z] + dp[d][z][y]);
            }
            swap(ans,ans2);
        }

        N /= 2;
        d++;
    }

    LL a = 0;
    REP(x,M) REP(y,M) chmax(a,ans[x][y]);
    cout << a << endl;


}