//Pascal
var
a: integer;
begin
readln(a);
if a > 0 then a := a + 20
else
a := a - 10;
writeln(a);
end.
//Pascal
var
a: integer;
begin
readln(a);
if a > 0 then a := a + 20
else
a := a - 10;
writeln(a);
end.