#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream in("zvon.in");
ofstream out("zvon.out");
const int N=100001;
vector<int> a[N];
int t[N], n;

bool cmp(int x, int y){
    return t[x]>t[y];
}

void citire(){
    int i,x,y;
    in>>n;
    for(i=1;i<n;i++)
       {
        in>>x>>y;
        a[x].push_back(y);
        }
}

void dfs(int x){
    int i,y;
    for(i=0;i<a[x].size();i++){
        y=a[x][i];
        dfs(y);
    }
    sort(a[x].begin(),a[x].end(),cmp);
    t[x]=0;
    for(i=0;i<a[x].size();i++){
        y=a[x][i];
        t[x]=max(t[x] , i+1+t[y]);
    }
}

int main()
{
    int TEST;
    in>>TEST;
    while(TEST>0){
        citire();
        dfs(1);
        out<<t[1]<<"\n";
        for(int i=1;i<n;i++){
            a[i].clear();
            t[i]=0;
        }

    TEST--;
    }



    return 0;
}