#include<iostream>
#include<string>
#include<vector>
using namespace std;

int main(){
	double n, a, b; cin >> n >> a >> b;
	vector<double> k(n);
	for(int i = 0; i <= n; i++) cin >> k[i];
	
	double aa = a, bb = b;
	
	double ans = k[0] * (bb -aa);
	for(int i = 1; i <= n; i++){
		aa *= a; bb *= b;
		ans += k[i] * (bb - aa) / (i + 1);
	}
	
	cout << (long)ans << endl;
}