#include <cmath>
#include <string>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int main() {
	long long N, A, B;
	cin >> N >> A >> B;
	long long val1 = A * (N - 1) - B * N; // all -1
	long long val2 = -A * (N - 1) - B * (N % 2); // -1, +1, -1, +1, ...
	cout << min(val1, val2) << endl;
	return 0;
}