#include <bits/stdc++.h>
std::ifstream in("zvon.in");
std::ofstream out("zvon.out");
using namespace std;
int n,t;
vector<int>G[100001];
void input()
{
    in >> n ;
    for(int i =1; i <n; ++i)
    {
        int x,y;
        in>>x>>y;
        G[x].push_back(y);
    }
}
int d[100001];
void dinamik(int nod)
{
    if(G[nod].size()==0 and nod !=1)d[nod]=1;
    else
    {
        for(size_t j = 0 ; j < G[nod].size(); ++j)
        {
            dinamik(G[nod][j]);
            int c1=d[nod];
            int c2=d[G[nod][j]]+1;
            int c3=G[nod].size();
            d[nod]=max(c1,max(c2,c3));
        }
    }
}

void reset()
{
    for(int i =1 ;i<=n ;++i)d[i]=0 , G[i].clear();
}


int main()
{
    in>>t;
    for(int i =1; i <=t ; ++i)
    {
        reset();
        input();
        dinamik(1);
        out<<d[1]<<"\n";
    }

    return 0;
}