#define  _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#pragma comment (linker, "/STACK:526000000")

#include "bits/stdc++.h"

using namespace std;
typedef string::const_iterator State;
#define eps 1e-11L
#define MAX_MOD 1000000007LL
#define GYAKU 500000004LL

#define MOD 998244353LL
#define seg_size 262144
#define pb push_back
#define mp make_pair
typedef long long ll;
#define REP(a,b) for(long long (a) = 0;(a) < (b);++(a))
#define ALL(x) (x).begin(),(x).end()

void init() {
    iostream::sync_with_stdio(false);
    cout << fixed << setprecision(20);
}


#define int ll

unsigned long xor128() {
    static unsigned long x = 123456789, y = 362436069, z = 521288629, w = 88675123;
    unsigned long t = (x ^ (x << 11));
    x = y; y = z; z = w;
    return (w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)));
}

void solve(){
    int n, p, query;
    cin >> n >> p >> query;
    vector<int> inputs;
    int ans = 0;
    REP(i, n) {
        int c;
        cin >> c;
        ans += c;
        inputs.push_back(c);
    }
    REP(i, n) {
        int val = (query - i) * p;
        inputs[i] = val - inputs[i];
    }
    sort(ALL(inputs));
    reverse(ALL(inputs));
    int final_ans = ans;
    REP(i, n) {
        ans += inputs[i];
        ans += 2 * i * p;
        final_ans = max(final_ans, ans);
    }
    cout << final_ans << endl;
}

#undef int
int main() {
    init();
    solve();
}
