#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main() {
    ll N,A,B; cin >> N >> A >> B;
    ll ans = numeric_limits<ll>::max();
    ans = min(ans, A * (N - 1) - B * N);
    if(N % 2 == 0) {
        ans = min(ans, -A * (N - 3) - 2 * B);
        ans = min(ans, -A * (N - 1));
    } else {
        ans = min(ans, -A * (N - 1) - B);
    }
    cout << ans << endl;
}