#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
#define rep(i, n) for (int64_t i = 0; i < (int64_t)(n); i++)
using namespace std;
int main() {
    double ans = 0;
    int64_t n; cin >> n;
    double a; cin >> a;
    double b; cin >> b;
    vector<double> k(n+1); rep(i, n+1) cin >> k.at(i);
    double memo;
    rep(i ,n+1) {
        memo = double((k[i])/double(i+1));
        rep(j ,i+1) memo *= double(b);
        ans += double(memo);
    }
    rep(i ,n+1) {
        memo = double((k[i])/double(i+1));
        rep(j ,i+1) memo *= double(a);
        ans -= double(memo);
    }
    cout << int(ans+0.01) << endl;
}