import java.util.*;
import java.io.*;

public class Main {
    static int c;
    static int v;
    static int[] dp;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int c = sc.nextInt();
        int v = sc.nextInt();
        int[] dp = new int[n * 2];
        int ans = Integer.MAX_VALUE;
        for (int i = 2; i < n * 2; i++) {
            dp[i] = c + v * (i - 1);
            for (int j = 2; j <= Math.sqrt(i); j++) {
                if (i % j == 0) {
                    dp[i] = Math.min(dp[i], dp[j] + c + v * (i / j - 1));
                    dp[i] = Math.min(dp[i], dp[i / j] + c + v * (j - 1));
                }
            }
            if (i >= n) {
                ans = Math.min(ans, dp[i]);
            }
        }
        System.out.println(ans);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String nextLine() throws Exception {
        return br.readLine();
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}