#include<fstream>
#include<algorithm>
#include<vector>
#define DIM 100005
using namespace std;
int t, n, i, maxim, x, y;
int d[DIM], viz[DIM], a[DIM];
vector<int> v[DIM];
ifstream fin("zvon.in");
ofstream fout("zvon.out");
void dfs(int nod){
    viz[nod] = 1;
    int nr = 0;
    int i;
    for(i = 0; i < v[nod].size(); i++){
        int vecin = v[nod][i];
        if(viz[vecin] == 0){
            dfs(vecin);
        }
        a[++nr] = d[vecin];
    }
    if(nr != 0){
        sort(a + 1, a + nr + 1);
        for(i = nr; i >= 1; i--){
            d[nod] = max(d[nod], a[i] + (nr - i + 1));
        }
    }
}
int main(){
    fin>> t;
    for(; t; t--){
        fin>> n;
        for(i = 1; i <= n; i++){
            d[i] = viz[i] = 0;
            v[i].clear();
        }
        for(i = 1; i < n; i++){
            fin>> x >> y;
            v[x].push_back(y);
        }
        dfs(1);
        fout<< d[1] <<"\n";
    }
    return 0;
}