#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
FILE *f=fopen("zvon.in","r"),*g=fopen("zvon.out","w");
vector <int> v[100001];
int n,i,t[100001],x,y,j;
int cmp(int a,int b){
    return t[a]>t[b];
}
void dfs(int k){
    for(int i=0;i<v[k].size();i++)
        dfs(v[k][i]);
    sort(v[k].begin(),v[k].end(),cmp);
    for(int i=0;i<v[k].size();i++)
        t[k]=max(t[k],t[v[k][i]]+i+1);
}
int main(){
    int T;
    fscanf(f,"%d",&T);
    for(i=1;i<=T;i++)
    {
        fscanf(f,"%d",&n);
        for(j=1;j<=n-1;j++){
            fscanf(f,"%d %d",&x,&y);
            v[x].push_back(y);
        }
        dfs(1);
        fprintf(g,"%d\n",t[1]);
        for(j=0;j<=n;j++){
            v[j].clear();
            t[j]=0;}
    }
    return 0;
}