#include <bits/stdc++.h>

#define show(x) cerr << #x << " = " << x << endl

using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    os << "sz=" << v.size() << "\n[";
    for (const auto& p : v) {
        os << p << ",";
    }
    os << "]\n";
    return os;
}

template <typename S, typename T>
ostream& operator<<(ostream& os, const pair<S, T>& p)
{
    os << "(" << p.first << "," << p.second
       << ")";
    return os;
}


constexpr ll MOD = 1e9 + 7;

template <typename T>
constexpr T INF = numeric_limits<T>::max() / 100;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    vector<vector<ll>> A(m, vector<ll>(m, 0));
    for (ll i = 0; i < m; i++) {
        for (ll j = 0; j < m; j++) {
            cin >> A[i][j];
        }
    }

    vector<vector<vector<ll>>> dp(m + 1, vector<vector<ll>>(m, vector<ll>(m, -INF<ll>)));
    for (ll i = 0; i < m; i++) {
        dp[0][i][i] = 0;
    }

    for (ll i = 0; i < m; i++) {
        for (ll j = 0; j < m; j++) {
            for (ll k = 0; k < m; k++) {
                for (ll l = 0; l < m; l++) {
                    if (dp[i][j][l] > -INF<ll>) {
                        dp[i + 1][j][k] = max(dp[i + 1][j][k], dp[i][j][l] + A[l][k]);
                    }
                }
            }
        }
    }

    ll maximum = 0;
    for (ll p = 1; p <= m; p++) {
        const ll loop = (n - 1) / p;
        const int rest = (n - 1) % p;
        ll maxi = 0;
        for (int i = 0; i < m; i++) {
            const ll loopscore = loop * dp[p][i][i];
            ll restmax = 0;
            for (int j = 0; j <= rest; j++) {
                ll tmp1 = 0;
                for (int k = 0; k < m; k++) {
                    tmp1 = max(tmp1, dp[j][k][i]);
                }
                ll tmp2 = 0;
                for (int k = 0; k < m; k++) {
                    tmp2 = max(tmp2, dp[rest - j][i][k]);
                }
                restmax = max(restmax, tmp1 + tmp2);
            }
            maxi = max(maxi, restmax + loopscore);
        }
        maximum = max(maximum, maxi);
    }
    cout << maximum << endl;

    return 0;
}