#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize("Ofast")

#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={1,0,-1,0,1,1,-1,-1,0};
const ll dx[9]={0,1,0,-1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
int main(){
  ll n,m;cin >> n >> m;
  ll dp[40][m][m];memset(dp,0,sizeof(dp));
  rep(i,m)rep(j,m){
    cin >> dp[0][i][j];
  }
  rep(i,39){
    rep(j,m){
      rep(k,m){
        rep(l,m){
          chmax(dp[i+1][j][k],dp[i][j][l]+dp[i][l][k]);
        }
      }
    }
  }
  vl v(m);
  n--;
  rep(i,40){
    if(n>>i&1){
      vl nv(m);
      rep(j,m){
        rep(k,m){
          chmax(nv[k],v[j]+dp[i][j][k]);
        }
      }
      swap(nv,v);
    }
  }
  cout << *max_element(all(v)) << endl;
}