#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;

ll n;
int m;
ll A[40][40], B[40][40];
ll x[40], y[40];

int main(){
  cin >> n >> m;
  
  rep(i,m){
    rep(j,m){
      cin >> A[i][j];
    }
  }

  rep(i,40){
    x[i] = 0;
    y[i] = 0;
  }

  n--;
  while(n>0){
    if(n&1){
      rep(i,40) y[i] = 0;
      rep(i,m){
        rep(j,m){
          y[j] = max(y[j], x[i] + A[i][j]);
        }
      }
      rep(i,40){
        x[i] = y[i];
      }
    }
    
    rep(i,40){
      rep(j,40){
        B[i][j] = 0;
      }
    }
    rep(i,m){
      rep(j,m){
        rep(k,m){
          B[i][k] = max(B[i][k], A[i][j] + A[j][k]);
        }
      }
    }
    rep(i,m){
      rep(j,m){
        A[i][j] = B[i][j];
      }
    }

    n>>=1;
  }

  ll ret = 0;
  rep(i,m) ret = max(ret, x[i]);

  cout << ret << endl;
  
  return 0;
}