#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
#define inf 0x3f3f3f3f

using namespace std;

ifstream f("zvon.in");
ofstream g("zvon.out");

vector < int > graf[100005];
int t, n, fii[100005];

void Clear(int n)
{
    for(int i = 1; i <= n; ++i) fii[i] = 1, graf[i].clear();
}

bool cmp(const int& i, const int& j)
{
    return fii[i] > fii[j];
}

void DFS(int nod)
{
    int last;
    for(int i = 0 ; i < graf[nod].size(); ++i) DFS(graf[nod][i]);
    fii[nod] = 0;
    if(graf[nod].size())
    {
        sort(graf[nod].begin(), graf[nod].end(), cmp);
        for(int i = 0; i < graf[nod].size(); ++i)
        {
            fii[nod] = max(fii[nod], fii[graf[nod][i]] + i + 1);
        }
    }

}


int main()
{
    int n,x,y;
    f >> t;
    for(; t; --t)
    {
        f >> n;
        for(int i = 1; i <= n - 1; ++i)
        {
            f >> x >> y;
            graf[x].push_back(y);
        }
        DFS(1);
        g << fii[1] << '\n';
        Clear(n);
    }
}