program del;
uses crt;
var l,i,n,m:integer;
st:string;
begin
clrscr;
readln(st);
i:=length(st);
while i>=1do
if st[i]='(' then
begin
n:=i;
while (st[n]<>')')and(n<=length(st)) do n:=n+1;
delete(st,i+1,n-i-1);
i:=i-1;
end
else i:=i-1;
write(st);
readln
end.