#include<fstream>
#include<iomanip>
#include<queue>
using namespace std;
struct yu
{
	int m;
	int v;
};
yu tmp;
int map[1001][1001];
queue<yu> dq;
int f[1001];
int main(void)
{
	ifstream fin("treec.in");
	ofstream fout("treec.out");
	int t;
	int n;
	int i,j,k;
	int p,q;
	fin>>t;
	for(;t;t--)
	{
		fin>>n;
		if(n==0||n==1)
		{
			fout<<"0.00"<<endl;
		//	t--;
			continue;
		}
		for(i=0;i<n;i++)
			for(j=0;j<n;j++)
				map[i][j]=0;
		for(p=1;p<n;p++)
		{
			fin>>i>>j>>k;
			map[i][j]=k;
		}
		tmp.m=0;
		tmp.v=0;
		dq.push(tmp);
		while(dq.size())
		{
			for(i=0;i<n;i++)
			{
				tmp=dq.front();
				if(map[tmp.m][i])
				{
					f[i]=map[tmp.m][i]+tmp.v;
					tmp.m=i;
					tmp.v=f[i];
					dq.push(tmp);
				}
			}
			dq.pop();
		}
		k=f[1];
		for(i=2;i<n;i++)
			if(f[i]>k)
				k=f[i];
		fout<<setiosflags(ios::fixed)<<setprecision(2)<<(double)k<<endl;
	}
	fin.close();
	fout.close();
	return 0;
}