#include <fstream>
#include <algorithm>
#include <vector>
#define DIM 100001
using namespace std;
ifstream fin("zvon.in");
ofstream fout("zvon.out");
int t,n,x,y,d[DIM];
vector<int> l[DIM];

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

void dfs(int nod) {
    for (int i=0;i<l[nod].size();i++)
        dfs(l[nod][i]);
    sort(l[nod].begin(),l[nod].end(),cmp);
    for (int i=0;i<l[nod].size();i++)
        d[nod]=max(d[nod],d[l[nod][i]]+i+1);
}

int main() {
    fin>>t;
    while (t--) {
        fin>>n;
        for (int i=1;i<=n;i++) {
            l[i].clear();
            d[i]=0;
        }
        for (int i=1;i<n;i++) {
            fin>>x>>y;
            l[x].push_back(y);
        }
        dfs(1);
        fout<<d[1]<<"\n";
    }
    return 0;
}