using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;

public class Program
{
    public void Proc() {
        Reader.IsDebug = false;
        int[] inpt = Reader.ReadLine().Split(' ').Select(a=>int.Parse(a)).ToArray();

        int ans = 50*inpt[0] + (int)((50*inpt[0]) / (0.8m + 0.2m*inpt[1]));
        Console.WriteLine(ans);


    }


    public class Reader {
        public static bool IsDebug = true;
        private static System.IO.StringReader SReader;
        private static string InitText = @"

2 31


";
        public static string ReadLine() {
            if(IsDebug) {
                if(SReader == null) {
                    SReader = new System.IO.StringReader(InitText.Trim());
                }
                return SReader.ReadLine();
            } else {
                return Console.ReadLine();
            }
        }

    }
    public static void Main(string[] args)
    {
        Program prg = new Program();
        prg.Proc();
    }
}