program string_12;
var sl,s:string; i:integer;
begin write('введите строку:'); readln(s);
sl:='';i:=1;s:=s+'.';
repeat
{for i:=1 to length(s) do}
if (s[i]=' ') or (s[i]=',') or (s[i]=';') or (s[i]='.') or (s[i]='!') or (s[i]='?')
then begin if sl[1]=sl[length(sl)] then writeln(sl);
sl:='';
end
else sl:=sl+s[i];
i:=i+1
until i>length(s);
readln;
end.