#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
using P=pair<ll,ll>;
using V=vector<ll>;
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,n) for(int i=1;i<=n;i++)

int main(){
    ll n,a,b;
    cin >> n >> a >> b;
    cout << min((n-1)*a*(-1)-n%2*b,(n-1)*a-b*n) << endl;
}