#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
    os<<p.first<<" "<<p.second;
    return os;
}
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}

template<typename T1,typename T2>
istream &operator>>(istream &is,pair<T1,T2>&p){
    is>>p.first>>p.second;
    return is;
}

template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}

int m;

vector<vector<ll>> Tropical(vector<vector<ll>> &a,vector<vector<ll>> &b){
    vector<vector<ll>> ret(m,vector<ll>(m,0));
    // i->j->k
    rep(i,m)rep(j,m)rep(k,m) chmax(ret[i][k],a[i][j]+b[j][k]);
    return ret;
}

vector<vector<ll>> PLight(vector<vector<ll>> a,ll n){
    vector<vector<ll>> ret(m,vector<ll>(m,0));

    while(n){
        if(n&1) ret=Tropical(ret,a);
        a=Tropical(a,a);
        n>>=1;
    }
    return ret;
}


signed main(){
    ll n;cin>>n;n--;
    cin>>m;
    vector<vector<ll>> mat(m,vector<ll>(m));

    rep(i,m)rep(j,m){
        cin>>mat[i][j];
    }
    mat=PLight(mat,n);
    ll res=0;
    rep(i,m)rep(j,m)chmax(res,mat[i][j]);

    cout<<res<<endl;
    return 0;
}