program main;
type
  integer=longint;
const
  maxn=1100;
var
  test:integer;
  n:integer;
  map:array[-2000..3000,1..1000] of integer;
  weight:array[1..maxn] of integer;
  coco:array[1..maxn,1..2] of integer;
  top:array[-2000..3000] of integer;

  procedure Fopen;
  begin
    assign(input,'coconuts.in');
    reset(input);
    assign(output,'coconuts.out');
    rewrite(output);
  end;

  procedure Fclose;
  begin
    close(input);
    close(output);
  end;

  procedure fall(x,k:integer);
  var
    w,v:integer;
  begin
    if top[x]=0 then
    begin
      top[x]:=1;
      map[x,1]:=k;
      coco[k,1]:=1; coco[k,2]:=x;
      exit;
    end;
    w:=weight[k];
    v:=weight[map[x,top[x]]];
    if (map[x-1,top[x]]=0) and (map[x+1,top[x]]=0) then
    begin
      if w>v then
      begin
        fall(x+1,map[x,top[x]]);
        map[x,top[x]]:=0;
        dec(top[x]);
        fall(x,k);
      end else
        fall(x-1,k);
      exit;
    end;
    if (map[x-1,top[x]]>0) and (map[x+1,top[x]]>0) then
    begin
      inc(top[x]);
      map[x,top[x]]:=k;
      coco[k,1]:=top[x]; coco[k,2]:=x;
      exit;
    end;
    if map[x-1,top[x]]=0 then
    begin
      if w>v then
      begin
        fall(x-1,map[x,top[x]]);
        map[x,top[x]]:=0;
        dec(top[x]);
        fall(x,k);
      end else
        fall(x-1,k);
      exit;
    end;
    if map[x+1,top[x]]=0 then
    begin
      if w>v then
      begin
        fall(x+1,map[x,top[x]]);
        map[x,top[x]]:=0;
        dec(top[x]);
        fall(x,k);
      end else
        fall(x+1,k);
      exit;
    end;
  end;
  procedure Solve;
  var
    i:integer;
    x,w:integer;
  begin
    readln(n);
    fillchar(map,sizeof(map),0);
    fillchar(top,sizeof(top),0);
    for i:=1 to n do
    begin
      readln(x,w);
      weight[i]:=w;
      fall(x,i);
    end;
    for i:=1 to n do writeln(coco[i,1],' ',coco[i,2]);
    if test>0 then writeln;
  end;
begin
  Fopen;
  readln(test);
  while test>0 do
  begin
    dec(test);
    Solve;
  end;
  Fclose;
end.