#include <iostream>
#include <string>
#include <algorithm>
#include <math.h>
#include <vector>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <cstdio>
#include <iomanip>
#include <list>

#define PI 3.14159265358979323846
#define mod 1000000007
#define pow9 1000000000
#define INF (1 << 30)

using namespace std;

int main() {
	long long n, a, b;
	cin >> n >> a >> b;
	long long ans1, ans2;
	if (n % 2 == 0) {
		ans1 = a * (-(n - 1));
	}
	else {
		ans1 = a * (-(n - 1)) - b;
	}

	ans2 = a * (n - 1) - b * n;

	cout << min(ans1, ans2) << endl;

}