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

//YukiCoder No.555 世界史のレポート
//https://yukicoder.me/problems/no/555
class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("6");
            WillReturn.Add("3 2");
            //12
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("10");
            WillReturn.Add("1 3");
            //15
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("100");
            WillReturn.Add("1000 1");
            //1099
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();

        int[] wkArr = { };
        Action<string> SplitAct = pStr =>
            wkArr = pStr.Split(' ').Select(X => int.Parse(X)).ToArray();

        SplitAct(InputList[0]);
        int N = wkArr[0];

        SplitAct(InputList[1]);
        int C = wkArr[0];
        int V = wkArr[1];

        //最小コスト[レポートの文字数,クリップボートの文字数]なDP表
        var DPArr = new Nullable<int>[N + 1, N + 1];
        DPArr[1, 0] = 0;


        for (int I = 0; I <= N; I++) {
            for (int J = 0; J <= N; J++) {
                if (DPArr[I, J].HasValue == false) continue;

                //コピーする場合
                int NewI = I;
                int NewJ = I;
                int NewCost = DPArr[I, J].Value + C;

                if (NewI > N) NewI = N;
                if (NewJ > N) NewJ = N;

                if (DPArr[NewI, NewJ].HasValue == false
                || DPArr[NewI, NewJ].Value > NewCost) {
                    DPArr[NewI, NewJ] = NewCost;
                }

                //ペーストする場合
                NewI = I + J;
                NewJ = J;
                NewCost = DPArr[I, J].Value + V;

                if (NewI > N) NewI = N;
                if (NewJ > N) NewJ = N;

                if (DPArr[NewI, NewJ].HasValue == false
                || DPArr[NewI, NewJ].Value > NewCost) {
                    DPArr[NewI, NewJ] = NewCost;
                }
            }
        }
        //for (int I = 0; I <= N; I++) {
        //    for (int J = 0; J <= N; J++) {
        //        Console.WriteLine("DPArr[{0},{1}]={2}", I, J, DPArr[I, J]);
        //    }
        //}

        int Answer = int.MaxValue;
        for (int I = 0; I <= N; I++) {
            if (DPArr[N, I].HasValue == false) continue;
            if (Answer > DPArr[N, I].Value)
                Answer = DPArr[N, I].Value;
        }
        Console.WriteLine(Answer);
    }
}