#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define INF INT_MAX/3
#define ALL(a) (a).begin(),(a).end()
#define CLR(a) memset(a,0,sizeof(a))

typedef long long int ll;

using namespace std;

int main(){
    while(true){
	int m,n;
	cin >> n >> m;
	vector< vector<double> > d(n,vector<double>(n,0.0) );
	if(n == 0 && m == 0) break;
	REP(i,n)REP(j,n) cin >> d[i][j];
	double ans = 0.0;
	vector<double> a(n);
	double dp[2][101];
	REP(i,2)REP(j,101) dp[i][j] = 0;
	REP(i,101) dp[0][i] = 1;
	REP(i,m-1){
	    REP(j,101) dp[1][i] = 0;

	    REP(j,n){
		dp[1][j] = dp[0][0] * d[j][0];
		REP(k,n){
		    dp[1][j] = max(dp[1][j],dp[0][k] * d[j][k]);
		}
	    }
	    swap(dp[0],dp[1]);
	}
	REP(i,n) ans = max(dp[0][i],ans);
	int t = ans * 1000;
	t = t % 10;
//	if(t >= 5) ans += 0.01;
	printf("%.2f\n",ans);
    }
    return 0;
}