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

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();
        c = sc.nextInt();
        v = sc.nextInt();
        dp = new int[n * 2];
        int ans = Integer.MAX_VALUE;
        for (int i = dp.length - 1; i >= n; i--) {
            ans = Math.min(ans, dfw(i));
        }
        System.out.println(ans);
    }
    
    static int dfw(int x) {
        if (x == 1) {
            return 0;
        }
        if (dp[x] == 0) {
            dp[x] = Integer.MAX_VALUE;
            for (int i = 1; i <= Math.sqrt(x); i++) {
                if (x % i == 0) {
                    int count = x / i;
                    dp[x] = Math.min(dp[x], dfw(i) + c + v * (count - 1));
                    if (i > 1) {
                        dp[x] = Math.min(dp[x], dfw(count) + c + v * (i - 1));
                    }
                }
            }
        }
        return dp[x];
    }
    
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    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 int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}