/* -*- coding: utf-8 -*-
 *
 * 572.cc: No.572 妖精の演奏 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_M = 30;

/* typedef */

typedef long long ll;
typedef ll mat[MAX_M][MAX_M];

/* global variables */

mat a, c, tmp;

/* subroutines */

inline void setmax(ll &a, ll b) { if (a < b) a = b; }

void matmaxsum(int m, const mat a, const mat b, mat c) {
  for (int i = 0; i < m; i++)
    for (int j = 0; j < m; j++) {
      c[i][j] = 0;
      for (int k = 0; k < m; k++) setmax(c[i][j], a[i][k] + b[k][j]);
    }
}

void matinit(mat a) { memset(a, 0, sizeof(mat)); }
void matcopy(const mat a, mat b) { memcpy(b, a, sizeof(mat)); }

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < m; i++)
    for (int j = 0; j < m; j++) scanf("%lld", &a[i][j]);

  n--;
  matinit(c);

  while (n > 0) {
    if (n & 1) {
      matmaxsum(m, c, a, tmp);
      matcopy(tmp, c);
    }

    matmaxsum(m, a, a, tmp);
    matcopy(tmp, a);
    n >>= 1;
  }

  ll maxv = 0;
  for (int i = 0; i < m; i++)
    for (int j = 0; j < m; j++) setmax(maxv, c[i][j]);

  printf("%lld\n", maxv);
  return 0;
}