const a=10;
	var b,c;
	procedure p;
		var d;
		begin
			d:=20;
			c:=d/a;
			c:=c+b;
		end;
	begin
		read (b);
		while b#0 do
			begin
				call p;
				write(2*c);
				read(b);
			end
	end.