You have two positive integers w and h. Your task is to count the number of rhombi which have the following properties: 

  * Have positive area. 
  * With vertices at integer points. 
  * All vertices of the rhombi are located inside or on the border of the rectangle with vertices at points (0, 0), (w, 0), (w, h), (0, h). In other words, for all vertices (xi, yi) of the rhombus the following conditions should fulfill: 0 ≤ xi ≤ w and 0 ≤ yi ≤ h. 
  * Its diagonals are parallel to the axis. 



Count the number of such rhombi.

Let us remind you that a rhombus is a quadrilateral whose four sides all have the same length.

Input

The first line contains two integers w and h (1 ≤ w, h ≤ 4000) — the rectangle's sizes.

Output

Print a single number — the number of sought rhombi.

Please do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specifier.

Examples

Input

2 2


Output

1


Input

1 2


Output

0

Note

In the first example there exists only one such rhombus. Its vertices are located at points (1, 0), (2, 1), (1, 2), (0, 1).
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Random;
import java.util.StringTokenizer;

public class A {

	public static void main(String[] args) throws IOException {

		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		long w = sc.nextInt(),h = sc.nextInt();
		
		long ans1=0,ans2=0;
	    for(int i=2;i<=w;i+=2)
	        ans1+=(w-i+1);
	    for(int i=2;i<=h;i+=2)
	        ans2+=(h-i+1);
		System.out.println(ans1*ans2);
	}

	static void ruffleSort(int[] a) {
		Random get = new Random();
		for (int i = 0; i < a.length; i++) {
			int r = get.nextInt(a.length);
			int temp = a[i];
			a[i] = a[r];
			a[r] = temp;
		}
		Arrays.sort(a);
	}

	static void ruffleSort(long[] a) {
		Random get = new Random();
		for (int i = 0; i < a.length; i++) {
			int r = get.nextInt(a.length);
			long temp = a[i];
			a[i] = a[r];
			a[r] = temp;
		}
		Arrays.sort(a);
	}

	static class Pair implements Comparable<Pair> {
		int x, y;

		Pair(int x, int y) {
			this.x = x;
			this.y = y;
		}

		@Override
		public int compareTo(Pair o) {
			return Integer.compare(this.x, o.x);
		}

	}

	static class FastScanner {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer("");

		String next() {
			while (!st.hasMoreTokens())
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			return st.nextToken();
		}

		int nextInt() {
			return Integer.parseInt(next());
		}

		int[] readArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++)
				a[i] = nextInt();
			return a;
		}

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

		double nextDouble() {
			return Double.parseDouble(next());
		}

		long nextLong() {
			return Long.parseLong(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}

	static int ceil(int x, int y) {
		return (x % y == 0 ? x / y : (x / y + 1));
	}

	static long ceil(long x, long y) {
		return (x % y == 0 ? x / y : (x / y + 1));
	}

	static int max(int x, int y) {
		return Math.max(x, y);
	}

	static int min(int x, int y) {
		return Math.min(x, y);
	}

	static int abs(int x) {
		return Math.abs(x);
	}

	static long abs(long x) {
		return Math.abs(x);
	}

	static int log2(int N) {
		int result = (int) (Math.log(N) / Math.log(2));
		return result;
	}

	static long max(long x, long y) {
		return Math.max(x, y);
	}

	static long min(long x, long y) {
		return Math.min(x, y);
	}

	static int min(int a[]) {
		int x = 1_000_000_00_9;
		for (int i = 0; i < a.length; i++)
			x = min(x, a[i]);
		return x;
	}

	static int max(int a[]) {
		int x = -1_000_000_00_9;
		for (int i = 0; i < a.length; i++)
			x = max(x, a[i]);
		return x;
	}

	static long min(long a[]) {
		long x = (long) 3e18;
		for (int i = 0; i < a.length; i++)
			x = min(x, a[i]);
		return x;
	}

	static long max(long a[]) {
		long x = -(long) 3e18;
		for (int i = 0; i < a.length; i++)
			x = max(x, a[i]);
		return x;
	}

	static int power(int x, int y) {
		int res = 1;
		while (y > 0) {
			if (y % 2 == 1)
				res = (res * x);
			y >>= 1;
			x = (x * x);
		}
		return res;
	}

	static long power(long x, long y) {
		long res = 1;
		while (y > 0) {
			if (y % 2 == 1)
				res = (res * x);
			y >>= 1;
			x = (x * x);
		}
		return res;
	}

	static void intsort(int[] a) {
		List<Integer> temp = new ArrayList<Integer>();
		for (int i = 0; i < a.length; i++)
			temp.add(a[i]);
		Collections.sort(temp);
		for (int i = 0; i < a.length; i++)
			a[i] = temp.get(i);
	}

	static void longsort(long[] a) {
		List<Long> temp = new ArrayList<Long>();
		for (int i = 0; i < a.length; i++)
			temp.add(a[i]);
		Collections.sort(temp);
		for (int i = 0; i < a.length; i++)
			a[i] = temp.get(i);
	}

	static void reverseintsort(int[] a) {
		List<Integer> temp = new ArrayList<Integer>();
		for (int i = 0; i < a.length; i++)
			temp.add(a[i]);
		Collections.sort(temp);
		Collections.reverseOrder();
		for (int i = 0; i < a.length; i++)
			a[i] = temp.get(i);
	}

	static void reverselongsort(long[] a) {
		List<Long> temp = new ArrayList<Long>();
		for (int i = 0; i < a.length; i++)
			temp.add(a[i]);
		Collections.sort(temp);
		Collections.reverseOrder();
		for (int i = 0; i < a.length; i++)
			a[i] = temp.get(i);
	}

	static class longpair implements Comparable<longpair> {
		long x, y;

		longpair(long x, long y) {
			this.x = x;
			this.y = y;
		}

		public int compareTo(longpair p) {
			return Long.compare(this.x, p.x);
		}
	}

	public static int gcd(int a, int b) {
		BigInteger b1 = BigInteger.valueOf(a);
		BigInteger b2 = BigInteger.valueOf(b);
		BigInteger gcd = b1.gcd(b2);
		return gcd.intValue();
	}

	public static long gcd(long a, long b) {
		BigInteger b1 = BigInteger.valueOf(a);
		BigInteger b2 = BigInteger.valueOf(b);
		BigInteger gcd = b1.gcd(b2);
		return gcd.longValue();
	}
}
