#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
const double eps = 1e-10;
const ll MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll<<50;
template<typename T>
void printv(const vector<T>& s) {
  for(int i=0;i<(int)(s.size());++i) {
    cout << s[i];
    if(i == (int)(s.size())-1) cout << endl;
    else cout << " ";
  }
}
template<typename T1, typename T2>
ostream& operator<<(ostream &os, const pair<T1, T2> p) {
  os << p.first << ":" << p.second;
  return os;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  ll n, p, q; cin >> n >> p >> q;
  vll c(n);
  ll sum = 0;
  for(int i=0;i<n;++i) {
    cin >> c[i];
    sum += c[i];
    c[i] = p * i + c[i];
  }
  sort(c.begin(), c.end());
  ll ans = sum;
  for(int i=0;i<=n;++i) {
    ans = max(ans, sum + p * q * i + p * i * (i - 1));
    if(i != n) sum -= c[i];
  }
  cout << ans << endl;
}

