#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

int main() {
	
	long long N,A,B;
	cin>>N>>A>>B;
	long long ans = Inf64;
	{
		ans = min(ans,(N-1)*A - B*N);
		ans = min(ans,(N-1)*A + B*N);
	}
	if(N%2==0){
		ans = min(ans,(N-1)*A*(-1));
	}
	else{
		ans = min(ans,(N-1)*A*(-1) + B);
		ans = min(ans,(N-1)*A*(-1) - B);
	}
	
	cout<<ans<<endl;
		
	
    return 0;
}