// -*- coding:utf-8-unix -*-
// #![feature(map_first_last)]
#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_macros)]
// use core::num;
use std::cmp::*;
use std::fmt::*;
use std::hash::*;
use std::io::*;
use std::iter::FromIterator;
use std::*;
use std::{cmp, collections, fmt, io, iter, ops, str};
const INF: i64 = 1223372036854775807;
const UINF: usize = INF as usize;
const LINF: i64 = 2147483647;
const INF128: i128 = 1223372036854775807000000000000;
const MOD1: i64 = 1000000007;
const MOD9: i64 = 998244353;
const MOD: i64 = MOD9;
// const MOD: i64 = MOD2;
const UMOD: usize = MOD as usize;
const M_PI: f64 = 3.14159265358979323846;
const NINF: i64 = -(1i64 << 60);

// use proconio::input;
// const MOD: i64 = INF;

use cmp::Ordering::*;
use std::collections::*;

use std::io::stdin;
use std::io::Write;

macro_rules! p {
    ($x:expr) => {
        //if expr
        println!("{}", $x);
    };
}

macro_rules! vp {
    // vector print separate with space
    ($x:expr) => {
        println!(
            "{}",
            $x.iter()
                .map(|x| x.to_string())
                .collect::<Vec<_>>()
                .join(" ")
        );
    };
}

macro_rules! d {
    ($x:expr) => {
        eprintln!("debug:{:?}", $x);
    };
}
macro_rules! yn {
    ($val:expr) => {
        if $val {
            println!("Yes");
        } else {
            println!("No");
        }
    };
}

macro_rules! map{
    // declear btreemap
    ($($key:expr => $val:expr),*) => {
        {
            let mut map = ::std::collections::BTreeMap::new();
            $(
                map.insert($key, $val);
            )*
            map
        }
    };
}

macro_rules! set{
    // declear btreemap
    ($($key:expr),*) => {
        {
            let mut set = ::std::collections::BTreeSet::new();
            $(
                set.insert($key);
            )*
            set
        }
    };
}

//input maskput
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

#[allow(dead_code)]
fn read_mat<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

#[allow(dead_code)]
fn readii() -> (i64, i64) {
    let mut vec: Vec<i64> = read_vec();
    (vec[0], vec[1])
}

#[allow(dead_code)]
fn readiii() -> (i64, i64, i64) {
    let mut vec: Vec<i64> = read_vec();
    (vec[0], vec[1], vec[2])
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
    let mut vec: Vec<usize> = read_vec();
    (vec[0], vec[1])
}

#[allow(dead_code)]
fn readff() -> (f64, f64) {
    let mut vec: Vec<f64> = read_vec();
    (vec[0], vec[1])
}

fn readcc() -> (char, char) {
    let mut vec: Vec<char> = read_vec();
    (vec[0], vec[1])
}

fn readuuu() -> (usize, usize, usize) {
    let mut vec: Vec<usize> = read_vec();
    (vec[0], vec[1], vec[2])
}

fn readiiii() -> (i64, i64, i64, i64) {
    let mut vec: Vec<i64> = read_vec();
    (vec[0], vec[1], vec[2], vec[3])
}

fn gcd(mut a: i64, mut b: i64) -> i64 {
    while b != 0 {
        let t = a % b;
        a = b;
        b = t;
    }
    a.abs()
}

fn lcm(a: i64, b: i64) -> i64 {
    a / gcd(a, b) * b
}

fn pow_i128(base: i64, mut e: usize) -> i128 {
    let mut r: i128 = 1;
    let mut b = base as i128;
    while e > 0 {
        if e & 1 == 1 {
            r *= b;
        }
        b *= b;
        e >>= 1;
    }
    r
}

fn main() {
    let v: Vec<i64> = read_vec();
    if v.len() < 3 {
        return;
    }
    let n = v[0] as usize;
    let a = v[1];
    let b = v[2];

    let mut k = Vec::<i64>::new();
    while k.len() < n + 1 {
        let t: usize = read();
        k.push(t as i64);
    }

    let mut d: i64 = 1;
    for i in 1..=n + 1 {
        d = lcm(d, i as i64);
    }

    let mut s: i128 = 0;

    for i in 0..=n {
        let pb = pow_i128(b, i + 1);
        let pa = pow_i128(a, i + 1);
        let diff = pb - pa;

        let coef = k[i];
        let mul = d / (i as i64 + 1);

        let term = (coef as i128) * diff * (mul as i128);
        s += term;
    }

    let ans: i64;
    if s >= 0 {
        ans = (s / d as i128) as i64;
    } else {
        let t = -s;
        let q = (t + d as i128 - 1) / d as i128;
        ans = (-q) as i64;
    }

    p!(ans);
}