program prog1136(input,output);
const s='      ';
type str=packed array [1..6] of char;
var c1:char;w1,w2,w:str;
procedure readword(var w:str);
var c:char;i:integer;
begin
 read(c);i:=1;
 while (c<>',') and (c<>'.') do begin
 w[i]:=c; i:=i+1; read(c); end;
 c1:=c;
end;
begin
readword(w);w1:=w;w2:=s;
while c1<>'.' do begin
readword(w); if w2<>s then if w2=w then write(w1,' '); w2:=w1; w1:=w;
end;
end.