var
 Numbers: array[0..10000-1] of LongInt;
 Trash: array[0..high(Numbers)] of string;

procedure DoIt;
var f:Text; i,j,L,k:LongInt; was:boolean;
begin
 i:=0;
 Assign(f, 'Rask.txt');
 Reset(f);
 while not eof(f) do
 begin
   read(f, Numbers[i]);
   readln(f, Trash[i]);
   i:=i+1;
 end;
 Close(f);

 L:=i;
 Assign(f, 'Error.txt');
 Rewrite(f);
 for i:=0 to L-1 do
   if Numbers[i]<>-1 then
   begin
     k:=Numbers[i];
     was:=false;
     for j:=i+1 to L-1 do
       if Numbers[j]=k then
       begin
         if not was then
           write(f, k, Trash[i]);
         write(f, ' e ', Numbers[j], Trash[j]);
         was:=true;
         Numbers[j]:=-1;
       end;
     if was then writeln(f);
   end;
 Close(f);
end;

begin
 DoIt;
end.