#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <tuple>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

typedef vector<ll> vec;
typedef vector<vec> mat;

int n, m;
ll a[30][30];

mat mult(mat &A, mat &B) {
    mat C(A.size(), vec(B[0].size()));
    for (int i = 0; i < A.size(); i++) {
        for (int k = 0; k < B.size(); k++) {
            for (int j = 0; j < B[0].size(); j++) {
                C[i][j] = max(C[i][j], A[i][k] + B[k][j]);
            }
        }
    }
    return C;
}

mat pow(mat A, ll n) {
    mat B(A.size(), vec(A.size()));
    while (n > 0) {
        if (n & 1) B = mult(B, A);
        A = mult(A, A);
        n >>= 1;
    }
    return B;
}

ll solve() {
    if (n == 1) return 0;
    mat A(m, vec(m));
    for (int i = 0; i < m; i++)
        for (int j = 0; j < m; j++)
            A[i][j] = a[i][j];

    mat B = pow(A, n-1);
    ll res = 0;
    for (int i = 0; i < m; i++)
        for (int j = 0; j < m; j++)
            res = max(res, B[i][j]);
    return res;
}

void input() {
    cin >> n >> m;
    for (int i = 0; i < m; i++)
        for (int j = 0; j < m; j++)
            cin >> a[i][j];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    cout << solve() << endl;
}