using System.Numerics;

public class Program
{
    public static void Main()
    {

        int num = int.Parse(Console.ReadLine() ?? string.Empty);
        string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;

        int a = int.Parse(str[0]);
        int b = int.Parse(str[1]);

        if(a == 0 || b == 0)
        {
            Console.WriteLine(0);
        }
        else
        {
            if((b-a)% 2 == 0)
            {
                if(a <= b)
                {
                    int s = (b / 2) + 1;
                    int cost = (s * a) + ((num - s) * b);
                    Console.WriteLine(cost);

                }
                else
                {
                    int s = b / 2;
                    int cost = (s * a) + ((num - s) * b);
                    Console.WriteLine(cost);

                }

            }
            else
            {
                int s = b / 2;
                int cost = (s*a) + ((num-s)*b);
                Console.WriteLine(cost);
            }
        }
    }
}