#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream f ("zvon.in");
ofstream g ("zvon.out");
vector<int>G[100010];
int timp[100010],n,x,y,test;
void dfs(int x){
    int numar=G[x].size();
    int k=0;
    vector <int>vec;
    for(int i=0;i<numar;++i){
        dfs(G[x][i]);
        vec.push_back(timp[G[x][i]]);
    }
    sort(vec.begin(),vec.end());
    k=vec.size();
    for(int i=0;i<k;++i){
        timp[x]=max(timp[x],vec[i]+k-i);
    }
}
int main()
{
    f>>test;
    while(test--){
        f>>n;
        for(int i=1;i<n;++i){
            f>>x>>y;
            G[x].push_back(y);
        }
        dfs(1);
        g<<timp[1]<<'\n';
        for(int i=1;i<=n;++i){
            timp[i]=0;
            G[x].clear();
        }
    }
    return 0;
}