#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
long long N,A,B;
long long get(long long X){
	long long Y = N-X;
	long long ret = (X-Y) * B;
	if(X==0||Y==0){
		ret += (N-1) * A;
	}
	else if(X==Y){
		ret -= (N-1) * A;
	}
	else{
		long long t = min(X,Y);
		ret -= (t+1) * A;
		ret += (N-1-(t+1)) * A;
	}
	return ret;
}
int main() {
	
	
	cin>>N>>A>>B;
	if(N==2){
		cout<<min(-A,A-B*2)<<endl;
		return 0;
	}
	long long ans = Inf64;
	ans = -N * B + A * (N-1);
	long long t = ans;
	t += (N/2) * (2*B-A*4);
	ans = min(ans,t);
	cout<<ans<<endl;
	
    return 0;
}