using namespace std;
#include <cstdio>
#include <string>
#include <vector>
#define pb push_back

int n;
vector<vector<int> > a;

int start[100001], nrfii[100001];


void solve()
{
  vector<int>::iterator it;
  int i, j;
  
  start[1]=0;
  
  int Q[100001], p=1, q=1;
  bool use[100001];
  memset(use, 0, sizeof(use));
  use[1]=1;
  Q[1]=1;
  int u;

  while(p<=q)
    {
      u=Q[p++];

      for(it=a[u].begin(), i=0;it!=a[u].end();++it,++i)
	{	
	  start[*it]=start[u]+i;
	  Q[++q]=*it;
	  
	}

    }

  int max=0;
  for(i=1;i<=n;++i)
    if(max<start[i]+nrfii[i]) max=start[i]+nrfii[i];

  printf("%d\n", max);
     

}

int main()
{
  int T, i, p, q;
  freopen("zvon.in","r",stdin);
  freopen("zvon.out","w",stdout);
  scanf("%d\n", &T);
  while(T--)
    {
      scanf("%d\n", &n);
      a.clear();
      a.resize(n+1);
      memset(nrfii, 0, sizeof(nrfii));
      memset(start, 0, sizeof(start));
      for(i=1;i<n;++i)
	{
	  scanf("%d %d\n", &p, &q);
	  a[p].pb(q);
	  ++nrfii[p];
	}
      solve();
    }
  return 0;

}