#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

ll N;
int M;
ll A[35][31][31];
ll B[35][31][31];





void solve() {
	int i,j,k,l,r,x,y,z; string s;
	
	
	cin>>N>>M;
	
	FOR(y,M) FOR(x,M) {
		cin>>A[0][y][x];
	}
	FOR(i,34) {
		FOR(x,M) FOR(y,M) {
			FOR(z,M) A[i+1][x][y]=max(A[i+1][x][y],A[i][x][z]+A[i][z][y]);
		}
	}
	
	N--;
	ll ret=0;
	FOR(i,34) {
		if(N&(1LL<<i)) {
			FOR(x,M) FOR(y,M) {
				FOR(z,M) B[i+1][x][y]=max(B[i+1][x][y],B[i][x][z]+A[i][z][y]);
				ret=max(ret,B[i+1][x][y]);
			}
		}
		else {
			FOR(x,M) FOR(y,M) B[i+1][x][y]=B[i][x][y];
		}
	}
	
	
	
	cout<<ret<<endl;
	
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}