type pelem=^elem;
     elem=record
       info:longint;
       next:pelem;
     end;
var fi,fo:text;
    n,i,j,t,max,v1,v2,nm,ct,vl,valo,k:longint;
    tati,nivel:array[1..100000]of pelem;
    tmin,niv,fii:array[1..100000]of longint;
function part(st,dr:longint):longint;
var i,j,s,aux:longint;
begin
  i:=st; j:=dr; s:=-1;
  while i<j do
    begin
      if fii[i]<fii[j] then
        begin
          aux:=fii[i];
          fii[i]:=fii[j];
          fii[j]:=aux;
          s:=-s;
        end;
      if s=1 then inc(i)
             else dec(j);
    end;
  part:=i;
end;
procedure qsort(st,dr:longint);
var p:longint;
begin
  if st<dr then
    begin
      p:=part(st,dr);
      qsort(st,p-1);
      qsort(p+1,dr);
    end;
end;
procedure qin(var first:pelem; vl:longint);
var p:pelem;
begin
  new(p);
  p^.info:=vl;
  p^.next:=first;
  first:=p;
end;
procedure qout(var first:pelem; var vl:longint);
var p:pelem;
begin
  vl:=first^.info;
  p:=first;
  first:=first^.next;
  dispose(p);
end;
procedure solv;
begin
  read(fi,n);
  niv[1]:=1; nm:=0;
  qin(nivel[1],1);
  for i:=1 to n-1 do
    begin
      read(fi,v1,v2);
      qin(tati[v1],v2);
      niv[v2]:=niv[v1]+1;
      qin(nivel[niv[v2]],v2);
      if niv[v2]>nm then nm:=niv[v2];
    end;
  for i:=nm-1 downto 1 do
   begin
    while (nivel[i]<>nil) do
      begin
        qout(nivel[i],vl);
        ct:=0;
        while (tati[vl]<>nil) do
          begin
            qout(tati[vl],valo);
            inc(ct);
            fii[ct]:=valo;
          end;
        qsort(1,ct);
        max:=-maxint;
        for j:=1 to ct do
          if tmin[fii[j]]+j>max then max:=tmin[fii[j]]+j;
        tmin[vl]:=max;
      end;
    end;
  writeln(fo,tmin[1]);
  for i:=1 to n do
    begin
      niv[i]:=0;
      tmin[i]:=0;
    end;
  if nivel[1]<>nil then qout(nivel[1],vl);
end;
begin
  assign(fi,'zvon.in'); reset(fi);
  assign(fo,'zvon.out'); rewrite(fo);
  read(fi,t);
  for k:=1 to t do
    solv;
  close(fi);
  close(fo);
end.