package yukicoder;

import java.util.*;

public class Q453 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double c = sc.nextDouble();
		double d = sc.nextDouble();
		/*
		 * 1000x+2000y max 3/4x+2/7y<=c 1/4x+5/7y<=d
		 */

		double max = 0;
		ArrayDeque<Pair> que = new ArrayDeque<>();
		que.add(new Pair(0, Math.min(7.0 / 2.0 * c, 7.0 / 5.0 * d)));
		que.add(new Pair(Math.min(4.0 / 3.0 * c, 4 * d), 0));
		que.add(new Pair(4.0 / 13.0 * (5 * c - 2 * d), 7 * (3 * d - c) / 13.0));
		while (!que.isEmpty()) {
			Pair p = que.poll();
			if (p.x < 0 || p.y < 0)
				continue;
			max = Math.max(max, 1000 * p.x + 2000 * p.y);
		}
		System.out.println(max);
	}

	static class Pair {
		double x;
		double y;

		public Pair(double x, double y) {
			this.x = x;
			this.y = y;
		}
	}
}