var
i:integer;
s:string;
begin
readln(s);
for i:=length(s) downto 1 do
if (s[i]<'a') or(s[i]>'z') then
delete(s,i,1);
writeln(s);
end.
var
i:integer;
s:string;
begin
readln(s);
for i:=length(s) downto 1 do
if (s[i]<'a') or(s[i]>'z') then
delete(s,i,1);
writeln(s);
end.