#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, a, b;
    cin >> n >> a >> b;
    ll lc = 1;
    for(int i = 1; i <= n + 1; i++) lc = lcm(lc, i);
    ll am = 1, bm = 1, v, ans = 0;
    for(int i = 0; i <= n; i++){
        cin >> v;
        am *= a, bm *= b;
        ans += (v * (bm - am)) * lc / (i + 1);
    }
    cout << ans / lc << '\n';
}