uses crt;
var st,buf:string;
begin
clrscr;
readln(st);
repeat
if (st[1]=' ') or (length(st)=0) then
begin
if buf[1]=buf[length(buf)] then
writeln(buf);
buf:='';
while st[1]=' ' do delete(st,1,1);
end
else
begin
while (st[1]<>' ') and (length(st)>0) do
begin
buf:=buf+st[1];
delete(st,1,1);
end;
end;
until (length(st)=0) and (length(buf)=0);
readln;
end.