#include <cstdio>
#include <vector>
#include <queue>
#include <algorithm>
#define N 100010

using namespace std;

int t,n,x,y,i,fii[N],kont,rez[N],V[N];
vector<int> L[N];
queue<int> C;

bool cmp(int i, int j)
{
    return (fii[i]>fii[j]);
}

void dfs(int nod)
{
    vector<int>::iterator it;
    for (it=L[nod].begin(); it!=L[nod].end(); it++)
    {
        dfs(*it);
        fii[nod]+=fii[*it];
    }
}

void zvon() //care de fapt e un bfs
{
    vector<int>::iterator it;
    for (C.push(1); !C.empty(); C.pop())
    {
        kont=0;
        for (it=L[C.front()].begin(); it!=L[C.front()].end(); it++)
        {
            V[++kont]=*it;
            C.push(*it);
        }
        sort(V+1,V+kont+1,cmp);
        for (i=1; i<=kont; i++) rez[V[i]]=rez[C.front()]+i;
    }
}

int main()
{
    freopen("zvon.in","r",stdin);
    freopen("zvon.out","w",stdout);
    scanf("%d\n",&t);
    while (t--)
    {
        scanf("%d\n",&n);
        for (i=1; i<n; i++)
        {
            scanf("%d %d\n",&x,&y);
            L[x].push_back(y);
            fii[x]++;
        }
        dfs(1);
        zvon();
        printf("%d\n",*max_element(rez+1,rez+n+1));
        for (i=1; i<n; i++) L[i].clear();
    }

    return 0;
}