package m.shin; import java.math.BigDecimal; import java.util.Scanner; public class Con445 { public static void main(String[] args) { Scanner s = new Scanner(System.in); BigDecimal a = new BigDecimal(s.next()) , b = new BigDecimal(s.next()); s.close(); b = b.multiply(new BigDecimal("0.2")).add(new BigDecimal("0.8")); BigDecimal c = a.multiply(new BigDecimal("50")).divide(b, BigDecimal.ROUND_DOWN); a = a.multiply(new BigDecimal("50")).add(c); System.out.println(a.toString()); } }