#include <bits/stdc++.h>
using namespace std;
 
// source:
// https://github.com/kth-competitive-programming/kactl/blob/main/content/data-structures/LineContainer.h
// supports insertion of linear functions and querying of MAXIMUM value of x for
// a given x for details on internal implementation, see LineContainer module
// alternatively, learn Li Chao Tree
inline namespace _LineContainer {
bool _Line_Comp_State;
struct Line {
	// k is slope, m is intercept, p is intersection point
	mutable ll k, m, p;
	bool operator<(const Line &o) const { return _Line_Comp_State ? p < o.p : k < o.k; }
};
 
struct LineContainer : multiset<Line> {
	long long div(long long a, long long b) { return a / b - ((a ^ b) < 0 && a % b); }
 
	bool isect(iterator x, iterator y) {
		if (y == end()) {
			x->p = LLONG_MAX;
			return false;
		}
		if (x->k == y->k) x->p = x->m > y->m ? LLONG_MAX : -LLONG_MAX;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
 
	void add(long long k, long long m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p) isect(x, erase(y));
	}
 
	long long query(long long x) {
		assert(!empty());
		_Line_Comp_State = 1;
		auto l = *lower_bound({0, 0, x});
		_Line_Comp_State = 0;
		return l.k * x + l.m;
	}
};
}  // namespace _LineContainer
 
long long N, A, B, C;
LineContainer lc;
 
int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
 
	cin >> N >> A >> B >> C;
	long long P = 0, a, dp = 0;
	for (int i = 1; i <= N; i++) {
		lc.add(-2 * A * P, dp + A * P * P - B * P);
		cin >> a;
		P += a;
		dp = lc.query(P) + A * P * P + B * P + C;
	}
	cout << dp << '\n';
}