#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
using namespace std;

class ConvexHullDynamic
{
    typedef long long coef_t;
    typedef long long coord_t;
    typedef long long val_t;

private:
    struct Line
    {
        coef_t a, b;
        double xLeft;

        enum Type {line, maxQuery, minQuery} type;
        coord_t val;

        explicit Line(coef_t aa=0, coef_t bb=0) : a(aa), b(bb), xLeft(-INFINITY), type(Type::line), val(0) {}
        val_t valueAt(coord_t x) const { return a*x+b; }
        friend bool areParallel(const Line& l1, const Line& l2) { return l1.a==l2.a; }
        friend double intersectX(const Line& l1, const Line& l2) { return areParallel(l1,l2)?INFINITY:1.0*(l2.b-l1.b)/(l1.a-l2.a); }
        bool operator<(const Line& l2) const
        {
            if (l2.type == line)
                return this->a     < l2.a;
            if (l2.type == maxQuery)
                return this->xLeft < l2.val;
            if (l2.type == minQuery)
                return this->xLeft > l2.val;
        }
    };

private:
    bool isMax; 
    std::set<Line>  hull;  

private:
    bool hasPrev(std::set<Line>::iterator it) { return it!=hull.begin(); }
    bool hasNext(std::set<Line>::iterator it) { return it!=hull.end() && std::next(it)!=hull.end(); }

    bool irrelevant(const Line& l1, const Line& l2, const Line& l3) { return intersectX(l1,l3) <= intersectX(l1,l2); }
    bool irrelevant(std::set<Line>::iterator it)
    {
        return hasPrev(it) && hasNext(it)
               && (    isMax && irrelevant(*std::prev(it), *it, *std::next(it))
                       || !isMax && irrelevant(*std::next(it), *it, *std::prev(it)) );
    }

    std::set<Line>::iterator updateLeftBorder(std::set<Line>::iterator it)
    {
        if (isMax && !hasPrev(it) || !isMax && !hasNext(it))
            return it;

        double val = intersectX(*it, isMax?*std::prev(it):*std::next(it));
        Line buf(*it);
        it = hull.erase(it);
        buf.xLeft = val;
        it = hull.insert(it, buf);
        return it;
    }

public:
    explicit ConvexHullDynamic(bool isMax): isMax(isMax) {}

    void addLine(coef_t a, coef_t b)
    {
        Line l3 = Line(a, b);
        auto it = hull.lower_bound(l3);

        if (it!=hull.end() && areParallel(*it, l3))
        {
            if (isMax && it->b < b || !isMax && it->b > b)
                it = hull.erase(it);
            else
                return;
        }

        it = hull.insert(it, l3);
        if (irrelevant(it)) { hull.erase(it); return; }

        while (hasPrev(it) && irrelevant(std::prev(it))) hull.erase(std::prev(it));
        while (hasNext(it) && irrelevant(std::next(it))) hull.erase(std::next(it));

        it = updateLeftBorder(it);
        if (hasPrev(it))
            updateLeftBorder(std::prev(it));
        if (hasNext(it))
            updateLeftBorder(std::next(it));
    }

    val_t getBest(coord_t x) const
    {
        Line q;
        q.val = x;
        q.type = isMax ? Line::Type::maxQuery : Line::Type::minQuery;

        auto bestLine = hull.lower_bound(q);
        if (isMax) --bestLine;
        return bestLine->valueAt(x);
    }
};

void solve() {
	ConvexHullDynamic cht = ConvexHullDynamic(false);
	int n; long long C;
	cin >> n >> C;
	vector<long long> h(n + 1), dp(n + 1);
	for (int i = 1; i <= n; i++) {
		cin >> h[i];
	}
	dp[1] = 0;
	cht.addLine(-2 * h[1], h[1] * h[1]);
	for (int i = 2; i <= n; i++) {
		dp[i] = cht.getBest(h[i]) + h[i] * h[i] + C;
		cht.addLine(-2 * h[i], dp[i] + h[i] * h[i]);
	}
	cout << dp[n] << endl;
}

int main() {
	solve();
	return 0;
}

Measured memory_bytes: 18944