#include <cstdio>
#include <algorithm>
#include <vector>
#define NMAX 100005

using namespace std;

int n,T,x,y;
int t[NMAX];
vector<int>v[NMAX];

int cmp(int r,int p)
{
    if (t[r] > t[p]) return 1;
    return 0;
}

void DFS(int nod)
{
    for(int i = 0; i < v[nod].size(); ++i)
        DFS(v[nod][i]);

    sort(v[nod].begin(),v[nod].end(),cmp);

    for(int i = 0; i < v[nod].size(); ++i)
        t[nod]=max(t[nod],t[v[nod][i]]+i+1);
}

void init()
{
    for(int i = 1; i <= n; ++i)
    {
        t[i]=0;
        v[i].resize(0);
    }
}

int main()
{
    freopen("zvon.in","r",stdin);
    freopen("zvon.out","w",stdout);
    scanf("%d",&T);
    while(T > 0)
    {
        --T;
        init();
        scanf("%d",&n);
        for(int i = 1; i < n; ++i)
        {
            scanf("%d%d",&x,&y);
            v[x].push_back(y);
        }
        DFS(1);
        printf("%d\n",t[1]);
    }
return 0;
}