fn run() {
    input! {
        n: i64,
        a: i64,
        b: i64,
    }
    let inf = std::i64::MAX / 2;
    type Mat = [[i64; 2]; 2];
    let mul = |a: &Mat, b: &Mat| -> Mat {
        let mut c = [[inf; 2]; 2];
        for (c, a) in c.iter_mut().zip(a.iter()) {
            for (a, b) in a.iter().zip(b.iter()) {
                for (c, b) in c.iter_mut().zip(b.iter()) {
                    *c = std::cmp::min(*c, *a + *b);
                }
            }
        }
        c
    };
    let mut t = [[0, inf], [inf, 0]];
    let mut r = [[b + a, -a - b], [-a + b, a - b]];
    let mut n = n - 1;
    while n > 0 {
        if n & 1 == 1 {
            t = mul(&t, &r);
        }
        r = mul(&r, &r);
        n >>= 1;
    }
    let ans = (t[0][0].min(t[0][1]) + b).min(t[1][0].min(t[1][1]) - b);
    println!("{}", ans);
}

fn main() {
    run();
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------