/* -*- coding: utf-8 -*-
 *
 * 2057.cc:  No.2057 Ising Model - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

/* typedef */

typedef long long ll;

/* global variables */

/* subroutines */

/* main */

int main() {
  ll n;
  int a, b;
  scanf("%lld%d%d", &n, &a, &b);

  ll f0 = a * (n - 1) - b * n;
  ll f1 = -a * (n - 1) - b * (n & 1);

  printf("%lld\n", min(f0, f1));
  return 0;
}