fn main() {
    let mut nab = String::new();
    std::io::stdin().read_line(&mut nab).ok();
    let nab: Vec<isize> = nab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nab[0];
    let a = nab[1];
    let b = nab[2];

    let mut result = (n-1) * a - n * b;
    if n % 2 == 1 {
        result = result.min(-a * (n - 1) - b);
    } else {
        result = result.min(-a * (n - 1));
        result = result.min(-a * (n - 3) - 2 * b);
    }
    println!("{}", result);
}