#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

int t, n;
int timp[100001];
vector < int > v[100001];

bool cmp(int a, int b)
{
    return timp[a] > timp[b];
}

void dfs(int nod)
{
    for (int i=0; i<v[nod].size(); i++)
        dfs(v[nod][i]);

    sort(v[nod].begin(), v[nod].end(), cmp);

    for (int i=0; i<v[nod].size(); i++)
        timp[nod] = max(timp[nod], timp[v[nod][i]] + i + 1);
}

int main()
{
    f >> t;
    while (t--)
    {
        f >> n;
        for (int i=1; i<n; i++)
        {
            int x, y; f >> x >> y;
            v[x].push_back(y);
        }

        dfs(1), g << timp[1] << "\n";

        for (int i=1; i<=n; i++)
        {
            v[i].clear();
            timp[i] = 0;
        }
    }
    return 0;
}