#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <atcoder/modint>

using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)


const i64 INF = 1001001001001001001;
using modint = atcoder::static_modint<998244353>;



int main(){
    i64 N,A,B; cin >> N >> A >> B;
    i64 ans = 0;
    ans = max(ans, N*B - (N-1)*A);
    ans = max(ans, N%2*B + (N-1)*A);
    if(N%2 == 0) ans = max(ans, B*2 + (N-3)*A);
    ans = -ans;
    cout << ans << '\n';
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;