#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
//#define int ll
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector< vi > vvi;
typedef vector< vvi > vvvi;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;
typedef complex<double> base;
typedef complex<int> point;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(),a.end()
#define RALL(a) a.rbegin(),a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for(int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>

#ifdef MAX_HOME
#define cerr cout
#else
#define cerr if (false) cerr
#endif

#define watch(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }


void err(istream_iterator<string> it) {}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
    cerr << *it << " = " << a << endl;
    err(++it, args...);
}

const double PI = 2 * acos(0.0);

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";

template <class T0, class T1>
inline ostream & operator << (ostream &out, pair<T0, T1> &a) {
    return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1, class T2>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2, T3> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ", " <<  get<3>(a) << "}";
}

template<class T>
inline ostream & operator << (ostream &out, vector<T> &a) {
    out << "[";
    fori (i, a.size())
        out << a[i] << vector<string>{", ", "]  "}[i + 1 == a.size()];
    return out;
}



void smain();

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

#ifdef MAX_HOME
    freopen("input.txt", "r", stdin);
    clock_t start = clock();
#endif
    cout << setprecision(12) << fixed;
    smain();
#ifdef MAX_HOME
    cout << "\n\n\n\nTOTAL EXECUTION TIME: " << float( clock () - start ) /  CLOCKS_PER_SEC << endl;
#endif
}

const int N = 2e5 + 9;

struct Line {
    ll a, b;
    Line() {}
    Line(ll a, ll b) : a(a), b(b) {}
    ll f(ll x) {
        return a * x + b;
    }
};

const ll oo = 1e12 + 100000;
#ifdef MAX_HOME
const int L = 1000;
#else
const int L = 1e6 + 9;
#endif

struct LiChaoTree {
    Line t[L << 2];

    LiChaoTree() {
        fill(t, t + (L << 2), Line(oo, oo));
    }

    void add_line(Line nw, int v = 1,  int tl = 0, int tr = L - 1) {
        bool lf = nw.f(tl) < t[v].f(tl);
        int tm = tl + tr >> 1;
        bool mid = nw.f(tm) < t[v].f(tm);
        if (mid) swap(nw, t[v]);
        if (tl == tr) return;
        if (mid != lf) add_line(nw, v << 1, tl, tm);
        else add_line(nw, v << 1 | 1, tm + 1, tr);
    }

    ll get(ll x, int v = 1, int tl = 0, int tr = L - 1) {
        ll cur = t[v].f(x);
        if (tl == tr) return cur;
        int tm = tl + tr >> 1;
        if (x <= tm) return min(cur, get(x, v << 1, tl, tm));
        return min(cur, get(x, v << 1 | 1, tm + 1, tr));
    }
};


void smain() {

    int n;
    ll c;
    cin >> n >> c;
    vl h(n);
    fori (i, n) cin >> h[i];
    vl dp(n, 0);
    dp[0] = 0;
    LiChaoTree tree;
    tree.add_line(Line(-2 * h[0], c + sqr(h[0])));
    for (int i = 1; i < n; ++i) {
        dp[i] = tree.get(h[i]) + sqr(h[i]);
        tree.add_line(Line(-2 * h[i], dp[i] + c + sqr(h[i])));
    }
    cout << dp[n - 1];
}

Measured memory_bytes: 65920