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).
// package programs;

import java.util.*;

import static java.lang.System.out;

import java.io.DataInputStream; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader; 

public class Main 
{ 
	static final long mod = (int)1e9+7;
	static final long M = (int)1e9+7;
	 
	
	static class Reader 
	{ 
		final private int BUFFER_SIZE = 1 << 16; 
		private DataInputStream din; 
		private byte[] buffer; 
		private int bufferPointer, bytesRead; 

		public Reader() 
		{ 
			din = new DataInputStream(System.in); 
			buffer = new byte[BUFFER_SIZE]; 
			bufferPointer = bytesRead = 0; 
		} 

		public Reader(String file_name) throws IOException 
		{ 
			din = new DataInputStream(new FileInputStream(file_name)); 
			buffer = new byte[BUFFER_SIZE]; 
			bufferPointer = bytesRead = 0; 
		} 

		public String next() throws IOException 
		{ 
			byte[] buf = new byte[64]; // line length 
			int cnt = 0, c; 
			while ((c = read()) != -1) 
			{ 
				if (c == '\n') 
					break; 
				buf[cnt++] = (byte) c; 
			} 
			return new String(buf, 0, cnt); 
		} 
		
		public int nextInt() throws IOException 
		{ 
			int ret = 0; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 
			do
			{ 
				ret = ret * 10 + c - '0'; 
			} while ((c = read()) >= '0' && c <= '9'); 

			if (neg) 
				return -ret; 
			return ret; 
		}
		int[] readArray(int n) throws IOException {
			int[] a=new int[n];
			for (int i=0; i<n; i++) a[i]=nextInt();
			return a;
		}

		public long nextLong() throws IOException 
		{ 
			long ret = 0; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 
			do { 
				ret = ret * 10 + c - '0'; 
			} 
			while ((c = read()) >= '0' && c <= '9'); 
			if (neg) 
				return -ret; 
			return ret; 
		} 

		public double nextDouble() throws IOException 
		{ 
			double ret = 0, div = 1; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 

			do { 
				ret = ret * 10 + c - '0'; 
			} 
			while ((c = read()) >= '0' && c <= '9'); 

			if (c == '.') 
			{ 
				while ((c = read()) >= '0' && c <= '9') 
				{ 
					ret += (c - '0') / (div *= 10); 
				} 
			} 

			if (neg) 
				return -ret; 
			return ret; 
		} 

		private void fillBuffer() throws IOException 
		{ 
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
			if (bytesRead == -1) 
				buffer[0] = -1; 
		} 

		private byte read() throws IOException 
		{ 
			if (bufferPointer == bytesRead) 
				fillBuffer(); 
			return buffer[bufferPointer++]; 
		} 

		public void close() throws IOException 
		{ 
			if (din == null) 
				return; 
			din.close(); 
		}

	}
	

	
	public static int digitSum(int n)
	{
		int sum =0;
		while(n > 0)
		{
			int last = n%10;
			sum+=last;
			n/=10;
		}
		return sum;
	}
	
	public static boolean isPrime(int n) {
		for(int i = 2;i*i<=n;i++)
		{
			if(n%i == 0)
			{
				return false;
			}
		}
		return true;
	}
	
	public static int gcd(int a, int b)
	{
		if(b == 0)
		 return a;
		
		else
		return gcd(b,a%b);
	}
	
	public static int traverser(int nums[], int n, int k) 
    { 
        int product = 1; 
        
        if (nums[n - 1] == 0 && k % 2 != 0) 
            return 0; 
  
       
        if (nums[n - 1] <= 0 && k % 2 != 0) { 
            for (int i = n - 1; i >= n - k; i--) 
                product *= nums[i]; 
            return product; 
        } 
        
        int i = 0;
  
        int j = n - 1; 
        if (k % 2 != 0) { 
            product *= nums[j]; 
            j--; 
            k--; 
        } 
        
        k >>= 1;   
		
        for (int l = 0; l < k; l++) { 
            int left_product = nums[i] * nums[i + 1]; 
  
            int right_product = nums[j] * nums[j - 1]; 
  
            if (left_product > right_product) { 
                product *= left_product; 
                i += 2; 
            } 
            else { 
                product *= right_product; 
                j -= 2; 
            } 
        } 
  
        return product; 
    } 
  
	
	public static int[] computePrefix(int arr[], int n)
	{
		int[] prefix = new int[n];
		prefix[0] = arr[0];
		for(int i = 1;i<n;i++)
		{
			prefix[i] = prefix[i-1]+arr[i];
		}
		
		return prefix;
	}
	
	public static int lcm(int a, int b)
	{
		return (a*b)/gcd(a,b);
	}
	
	public static int phi(int n)  //euler totient function
    { 
        int result = 1; 
        for (int i = 2; i < n; i++) 
            if (gcd(i, n) == 1) 
                result++; 
        return result; 
    }
	
	public static int check(int n)
	{
		int cl = 0;
		while(n > 0)
		{
			if(n%10 == 4 || n%7 == 10)
			{
				cl++;
				n/=10;
			}
		}
		
		return cl;
	}
	
	public static void main(String[] args) throws IOException 
	{ 
		Reader sc=new Reader();
				
		int w = sc.nextInt();
		int h = sc.nextInt();
		
		long ans = 0;
		for(int i = 0;i<=w;i++)
		{
			for(int j = 0;j<=h;j++)
			{
				ans += (((h-j) / 2) * Math.min(i,w-i));
			}
		}
		System.out.println(ans);
	}		
}


 