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

int main(){
  using ll=long long;
  using lll=__int128_t;
  ll g=1;
  for (int i=1;i<=11;i++) g=lcm(g,i);
  ll n,a,b;
  cin>>n>>a>>b;
  vector<ll> k(n+1);
  for (int i=0;i<=n;i++) cin>>k[i];
  ll a2=1,b2=1;
  lll s=0;
  for (int i=0;i<=n;i++){
    a2*=a;
    b2*=b;
    lll x=b2-a2;
    s+=x*k[i]*(g/(i+1));
  }
  cout<<ll(s/g)<<endl;
}