import java.util.*; import java.math.BigDecimal; public class Point { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int a = sc.nextInt(); BigDecimal b = new BigDecimal(sc.next()); BigDecimal c = new BigDecimal("0.8"); BigDecimal d = new BigDecimal("0.2"); BigDecimal e = new BigDecimal(50*a); System.out.println(a * 50 + e.divide(c.add(d.multiply(b))).intValue()); } }