#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T> T RoundOff(T a){ return int(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }
template<class T, class C> pair<T, C> mp(T a, C b){ return make_pair(a, b); }

int n, m;
double table[128][128], memo[128][128];

// m=3
// p=0,prv=2
// p=1,prv=0
// p=2,prv=1
double rec(int p, int prv)
{
	if(p == m - 2) return *max_element(table[prv], table[prv] + 128);
	if(memo[p][prv] != -1) return memo[p][prv];
	
	int sld;
	double res = -1;
	rep(i, n)
	{
		double sub = rec(p + 1, i);
		
		if(res < sub)
		{
			res = sub;
			sld = i;
		}
	}
	
	return memo[p][prv] = table[prv][sld] * res;
}

int main()
{
	while(cin >> n >> m && n)
	{
		rep(i, n) rep(j, n) cin >> table[i][j];
		
		double ans = 0;
		
		rep(i, n)
		{		
			rep(j, 128) rep(k, 128) memo[j][k] = -1;

			chmax(ans, rec(0, i));
		}
		
		printf("%.2f\n", ans);
	}	
}