import java.util.*;

public class Main {
    static int copy;
    static int paste;
    static long[] dp;
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	copy = sc.nextInt();
    	paste = sc.nextInt();
    	dp = new long[n + 1];
    	System.out.println(dfw(n));
	}
	
	static long dfw(int x) {
	    if (x == 1) {
	        return 0;
	    }
	    if (dp[x] == 0) {
	        dp[x] = Long.MAX_VALUE;
	        for (int i = 1; i * 2 <= x + 1; i++) {
	            dp[x] = Math.min(dp[x], dfw(i) + (x - 1) / i * paste + copy);
	        }
	    }
	    return dp[x];
	}
	
}