import java.util.*;
 
public class Main {
	public static void main(String[] args) {
 
	Scanner sc  = new Scanner(System.in);
        
    int cnt = 0;

	int  i1 = 0 ,i2 = 0, i3 = 0;
	long L1 = 0, L2 = 0, L3 = 0;
	char ch;
	String str = "";
		
    int A  = Integer.parseInt(sc.next());
    int B  = Integer.parseInt(sc.next());

    double ans =  50 * A + (int)( ( 50 * A ) / ( 0.8 + (0.2*B)  ) )  ;


        System.out.print( (int)ans );
        System.out.println();
	}
        
}