#include <bits/stdc++.h>
using namespace std;

const int MAXN = int(5e9);
const int MAXM = 30;

long long N;
int M;
int A[MAXM][MAXM];
long long dp[40][MAXM][MAXM];

long long dp2[MAXM];

signed main() {
  ios::sync_with_stdio(false);
  cin >> N;
  cin >> M;
  for (int i = 0; i < M; ++i) {
    for (int j = 0; j < M; ++j) {
      cin >> A[i][j];
    }
  }
  memset(dp, 0xc0, sizeof(dp));
  for (int i = 0; i < M; ++i) {
    dp[0][i][i] = 0;
  }
  for (int i = 0; i + 1 < 40; ++i) {
    for (int j = 0; j < M; ++j) {
      for (int k = 0; k < M; ++k) {
        for (int l = 0; l < M; ++l) {
          for (int m = 0; m < M; ++m) {
            dp[i + 1][j][m] = max(dp[i + 1][j][m], dp[i][j][k] + A[k][l] + dp[i][l][m]);
          }
        }
      }
    }
  }
  --N;
  for (int i = 0; i < 40; ++i) {
    if (~N >> i & 1LL) continue;
    static long long tmp[MAXM];
    memset(tmp, 0xc0, sizeof(tmp));
    for (int j = 0; j < M; ++j) {
      for (int k = 0; k < M; ++k) {
        for (int l = 0; l < M; ++l) {
          tmp[l] = max(tmp[l], dp2[j] + A[j][k] + dp[i][k][l]);
        }
      }
    }
    for (int j = 0; j < M; ++j) {
      dp2[j] = tmp[j];
    }
  }
  cout << *max_element(dp2, dp2 + M) << endl;
  return 0;
}