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

int main(){
    int n; cin >> n;
    ll a, b; cin >> a >> b;
    ll iv = 1;
    for (int i = 0; i <= n; i++){
        iv *= (i + 1) / gcd(iv, i + 1);
    }
    ll sum = 0;
    ll ap = 1, bp = 1;
    for (int i = 0; i <= n; i++){
        ap *= a;
        bp *= b;
        ll k; cin >> k;
        sum += k * (bp - ap) * (iv / (i + 1));
    }
    ll ans = sum / iv;
    if (sum % iv != 0 && sum < 0){
        ans++;
    }
    cout << ans << '\n';
}