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

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll N,A,B; cin >> N >> A >> B;
    ll ans = numeric_limits<ll>::max();
    ans = min(ans, A * (N - 1) - B * N);
    ans = min(ans, A * (N - 1) * (-1) + B * (N % 2 == 0 ? 0 : -1));
    cout << ans << endl;
}