class Main {
  public static void main(String[] args){
    var sc = new java.util.Scanner(System.in);
    int d = sc.nextInt();
    int a = sc.nextInt();
    int b = sc.nextInt();
    int x = a < b ? d : 0;
    int ans = x * a + (d - x) * b;
    System.out.println(ans);
  }
}