ворд лен к

program wordlwordlenk;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
s,ps,s1:ansistring;
f,q:text;
i:LongInt;
k,met:int64;
begin
  Assign(f,'input.txt');
  Reset(f);
  Assign(q,'output.txt');
  Rewrite(q);
  Readln(f,k);
  i:=1;
  met:=1;
  while not(eof(f)) do
  begin
     readln(f,s);
     i:=1;
     for i:=1 to length(s) do
	   begin
         if not(s[i] in[ '.' , ',' , ';' , ':' , '?' , '!' , ' ' ]) then
         begin
             ps:=ps+s[i];
		      	 met:=1;
         end
         else
         begin
		     if (met=1) and (length(ps)=k) and (i mod 2=1) then
		   	 begin
			     s1:=s1+ps+' ';
			  	 met:=0;
			   end;
             ps:='';
         end;
     end;
     if length(s1)=0 then Writeln(q,'-1')
     else  Writeln(q,s1);
	 s1:='';
	 ps:='';
  end;
  Close(f);
  Close(q);
end.