#include <stdio.h>
#include <vector>
#include <queue>
#include <list>
#include <set>
#include <algorithm>
#include <utility>
#include <string>
using namespace std;
#define FOR(i,a,b) for (typeof a i=a;i<=b;i++)
#define fori(it,v) for (typeof ((v).begin()) it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define mp make_pair
#define fs first
#define ss second
#define all(c) c.begin(),c.end()
int maxv;
bool maxc(const pair<int,int> &a,const pair<int,int> &b)
{
	return a.fs>b.fs?1:0;
}
int b[100100];
vector<vector<pair<int,int> > >  a(100100);
void dfs(int x)
{
	fori(it,a[x])
		dfs(it->ss);
	maxv=0;
	fori(it,a[x])
		it->fs=b[it->ss];
	sort(all(a[x]),maxc);
	fori(it,a[x])
		if (it->fs+it-a[x].begin()+1>maxv)
			maxv=it->fs+it-a[x].begin()+1;
	b[x]=maxv;
}
int main()
{
	int n,t,x,y;
	FILE *in,*out;
	in=fopen("zvon.in","r");
	out=fopen("zvon.out","w");
	fscanf(in,"%d",&t);
	for(;t;t--)
	{
		fscanf(in,"%d",&n);
		FOR(i,1,n)
		{
			b[i]=0;
			a[i].erase(all(a[i]));
		}
		FOR(i,2,n)
		{
			fscanf(in,"%d%d",&x,&y);
			a[x].pb(mp(0,y));
		}
		dfs(1);
		fprintf(out,"%d\n",b[1]);

	}
	return 0;
}