#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n; cin >> n;
    int m; cin >> m;
    vector<vector<vector<ll>>> d(35, vector<vector<ll>>(m, vector<ll>(m)));
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < m; ++j) {
            cin >> d[1][i][j];
        }
    }
    for (int i = 2; i < 35; ++i) {
        for (int j = 0; j < m; ++j) {
            for (int k = 0; k < m; ++k) {
                for (int l = 0; l < m; ++l) {
                    for (int p = 0; p < m; ++p) {
                        d[i][j][p] = max(d[i][j][p], d[i-1][j][k] + d[1][k][l] + d[i-1][l][p]);
                    }
                }
            }
        }
    }
    vector<vector<ll>> res(m, vector<ll>(m));
    bool f = false;
    for (int i = 0; i < 35; ++i) {
        if (!((1LL<<i)&n)) continue;
        vector<vector<ll>> nres(m, vector<ll>(m));
        for (int j = 0; j < m; ++j) {
            for (int k = 0; k < m; ++k) {
                for (int l = 0; l < m; ++l) {
                    for (int p = 0; p < m; ++p) {
                        if(f) nres[j][p] = max(nres[j][p], res[j][k] + d[1][k][l] + d[i][l][p]);
                        else nres[j][p] = d[i][j][p];
                    }
                }
            }
        }
        f = true;
        swap(res, nres);
    }
    ll mx = 0;
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < m; ++j) {
            mx = max(mx, res[i][j]);
        }
    }
    cout << mx << endl;
}