import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		long n = Long.parseLong(sa[0]);
		int a = Integer.parseInt(sa[1]);
		int b = Integer.parseInt(sa[2]);
		br.close();

		long v1 = (n - 1) * a - n * b;
		long n1 = n / 2;
		long n2 = n - n1;
		long v2 = (n - 1) * -a - n1 * b + n2 * b;
		long v3 = (n - 1) * -a + n1 * b - n2 * b;
		long ans = Math.min(Math.min(v1, v2), v3);
		System.out.println(ans);
	}
}