import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.List;

public class Main {

	private static final String NO = "NO";
	private static final String YES = "YES";
	InputStream is;
	PrintWriter out;
	String INPUT = "";

	private static final long MOD = 1000000007;
	private static final int MAXN = 200001;

	void solve() {
		int T = 1;
		for (int i = 0; i < T; i++)
			solve(i);
	}

	static int max_x = (int) (1e6 + 1);

	void solve(int T) {
		int n = ni();
		long C = nl();
		long ans = 0;
		LiChowTree lTree = new LiChowTree();
		for (int i = 0; i < n; ++i) {
			int h = ni();
			long h2 = 1L * h * h;
			if (i > 0)
				ans = lTree.query(h, 1, max_x, 1) + h2;
			lTree.add(new Line(-2 * h, h2 + C + ans), 1, max_x, 1);
		}
		out.print(ans);
	}

	// a^b
	long power(long a, long b) {
		long x = 1, y = a;
		while (b > 0) {
			if (b % 2 != 0) {
				x = (x * y) % MOD;
			}
			y = (y * y) % MOD;
			b /= 2;
		}
		return x % MOD;
	}

	private long gcd(long a, long b) {
		while (a != 0) {
			long tmp = b % a;
			b = a;
			a = tmp;
		}
		return b;
	}

	void run() throws Exception {
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);

		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if (!INPUT.isEmpty())
			tr(System.currentTimeMillis() - s + "ms");
	}

	public static void main(String[] args) throws Exception {
		new Main().run();
	}

	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;

	private int readByte() {
		if (lenbuf == -1)
			throw new InputMismatchException();
		if (ptrbuf >= lenbuf) {
			ptrbuf = 0;
			try {
				lenbuf = is.read(inbuf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (lenbuf <= 0)
				return -1;
		}
		return inbuf[ptrbuf++];
	}

	private boolean isSpaceChar(int c) {
		return !(c >= 33 && c <= 126);
	}

	private int skip() {
		int b;
		while ((b = readByte()) != -1 && isSpaceChar(b))
			;
		return b;
	}

	private double nd() {
		return Double.parseDouble(ns());
	}

	private char nc() {
		return (char) skip();
	}

	private String ns() {
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != '
									// ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	private char[] ns(int n) {
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while (p < n) {
			if (!(isSpaceChar(b)))
				buf[p++] = (char) b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}

	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for (int i = 0; i < n; i++)
			map[i] = ns(m);
		return map;
	}

	private int[] na(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = ni();
		return a;
	}

	private List<Integer> na2(int n) {
		List<Integer> a = new ArrayList<Integer>();
		for (int i = 0; i < n; i++)
			a.add(ni());
		return a;
	}

	private int[][] na(int n, int m) {
		int[][] a = new int[n][];
		for (int i = 0; i < n; i++)
			a[i] = na(m);
		return a;
	}

	private int ni() {
		int num = 0, b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-') {
			minus = true;
			b = readByte();
		}

		while (true) {
			if (b >= '0' && b <= '9') {
				num = num * 10 + (b - '0');
			} else {
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private long[] nl(int n) {
		long[] a = new long[n];
		for (int i = 0; i < n; i++)
			a[i] = nl();
		return a;
	}

	private long[][] nl(int n, int m) {
		long[][] a = new long[n][];
		for (int i = 0; i < n; i++)
			a[i] = nl(m);
		return a;
	}

	private long nl() {
		long num = 0;
		int b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-') {
			minus = true;
			b = readByte();
		}

		while (true) {
			if (b >= '0' && b <= '9') {
				num = num * 10 + (b - '0');
			} else {
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private static void tr(Object... o) {
		System.out.println(Arrays.deepToString(o));
	}

	static long INF = (long) (1e17 + 5);

	static class LiChowTree {
		static Line[] lines;

		LiChowTree() {
			lines = new Line[4 * max_x];
			for (int i = 1; i < 4 * max_x; i++) {
				lines[i] = new Line(0, INF);
			}
		}

		void add(Line curL, int a, int b, int i) {
			int mid = (a + b) / 2;
			boolean left = curL.getY(a) < lines[i].getY(a);
			boolean middle = curL.getY(mid) < lines[i].getY(mid);
			;
			if (middle) {
				long m_cur = curL.m;
				long b_cur = curL.b;
				curL.m = lines[i].m;
				curL.b = lines[i].b;
				lines[i].m = m_cur;
				lines[i].b = b_cur;
			}
			if (b - a == 1)
				return;
			if (left != middle)
				add(curL, a, mid, 2 * i);
			else
				add(curL, mid, b, 2 * i + 1);
		}

		long query(int x_val, int a, int b, int i) {
			int mid = (a + b) / 2;
			long val = lines[i].getY(x_val);
			if (b - a == 1)
				return val;
			if (x_val < mid)
				return Math.min(val, query(x_val, a, mid, i * 2));
			else
				return Math.min(val, query(x_val, mid, b, i * 2 + 1));
		}
	}

	static class Line {
		long m, b;

		Line(long m, long b) {
			this.m = m;
			this.b = b;
		}

		long getY(int x) {
			return this.m * x + this.b;
		}
	}
}

Measured memory_bytes: 184512