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 javax.print.DocFlavor;
import javax.swing.plaf.basic.BasicInternalFrameTitlePane;
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.nio.Buffer;
import java.sql.BatchUpdateException;
import java.util.*;
import java.util.stream.Stream;
import java.util.Vector;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import static java.lang.Math.*;
import java.util.*;
import java.nio.file.StandardOpenOption;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Iterator;
import java.util.PriorityQueue;

public class icpc
{
    public static void main(String[] args)throws IOException
    {
        Reader in = new Reader();

        int a = in.nextInt();
        int b = in.nextInt();
        long ans = 0L;
        for(int i=2;i<=a;i+=2)
            for(int j=2;j<=b;j+=2)
                ans += (a - i + 1) * (b - j + 1);
        System.out.println(ans);
    }
}
class Game
{
    int x;
    int y;
    Game(int a,int b)
    {
        this.x = a;
        this.y = b;
    }
}
class MergeSort
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]
    void merge(long arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        long L[] = new long [n1];
        long R[] = new long [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(long arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }
}
class Node
{
    String a;
    String b;
    Node(String s1,String s2)
    {
        this.a = s1;
        this.b = s2;
    }
    @Override
    public boolean equals(Object ob)
    {
        if(ob == null)
            return false;
        if(!(ob instanceof Node))
            return false;
        if(ob == this)
            return true;
        Node obj = (Node)ob;
        if(this.a.equals(obj.a) && this.b.equals(obj.b))
            return true;
        return false;
    }

    @Override
    public int hashCode()
    {
        return (int)this.a.length();
    }
}
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 readLine() 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;
    }

    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();
    }
}
class SegmentTree
{
    public int nextPowerOfTwo(int num)
    {
        if(num == 0)
            return 1;
        if(num > 0 && (num & (num - 1)) == 0)
            return num;
        while((num &(num - 1)) > 0)
        {
            num = num & (num - 1);
        }
        return num << 1;
    }

}
class FenwickTree
{
    public void update(long[] fenwickTree,long delta,int index)
    {
        index += 1;
        while(index < fenwickTree.length)
        {
            fenwickTree[index] += delta;
            index = index + (index & (-index));
        }
    }
    public long prefixSum(long[] fenwickTree,int index)
    {
        long sum = 0L;
        index += 1;
        while(index > 0)
        {
            sum += fenwickTree[index];
            index -= (index & (-index));
        }
        return sum;
    }
}
class SegmentTree1
{
    public int nextPowerOfTwo(int num)
    {
        if(num == 0)
            return 1;
        if(num > 0 && (num & (num - 1)) == 0)
            return num;
        while((num &(num - 1)) > 0)
        {
            num = num & (num - 1);
        }
        return num << 1;
    }
    public int[] createSegmentTree(int[] input)
    {
        int np2 = nextPowerOfTwo(input.length);
        int[] segmentTree = new int[np2 * 2 - 1];

        for(int i=0;i<segmentTree.length;i++)
            segmentTree[i] = Integer.MAX_VALUE;

        constructSegmentTree(segmentTree,input,0,input.length-1,0);
        return segmentTree;

    }
    private void constructSegmentTree(int[] segmentTree,int[] input,int low,int high,int pos)
    {
        if(low == high)
        {
            segmentTree[pos] = input[low];
            return;
        }
        int mid = (low + high)/ 2;
        constructSegmentTree(segmentTree,input,low,mid,2*pos + 1);
        constructSegmentTree(segmentTree,input,mid+1,high,2*pos + 2);
        segmentTree[pos] = Math.min(segmentTree[2*pos + 1],segmentTree[2*pos + 2]);
    }
    public int rangeMinimumQuery(int[] segmentTree,int qlow,int qhigh,int len)
    {
        return rangeMinimumQuery(segmentTree,0,len - 1,qlow,qhigh,0);
    }
    private int rangeMinimumQuery(int[] segmentTree,int low,int high,int qlow,int qhigh,int pos)
    {
        if(qlow <= low && qhigh >= high)
        {
            return segmentTree[pos];
        }
        else if(qlow > high || qhigh < low)
        {
            return Integer.MAX_VALUE;
        }
        int mid = (low + high)/2;
        return Math.min(rangeMinimumQuery(segmentTree,low,mid,qlow,qhigh,2*pos+1),rangeMinimumQuery(segmentTree,mid+1,high,qlow,qhigh,2*pos+2));
    }
    public void updateSegmentTreeRangeLazy(int[] input,int[] segmentTree,int[] lazy,int startRange,int endRange,int delta)
    {
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,0,input.length-1,0);
    }
    private void updateSegmentTreeRangeLazy(int[] input,int[] segmentTree,int[] lazy,int startRange,int endRange,int delta,int low,int high,int pos)
    {
        if(low > high)
        {
            return;
        }
        if(lazy[pos] != 0)
        {
            segmentTree[pos] += lazy[pos];
            if(low != high)
            {
                lazy[2*pos+1] += lazy[pos];
                lazy[2*pos + 2] += lazy[pos];
            }
            lazy[pos] = 0;
        }
        if(startRange > high || endRange < low)
            return;
        if(startRange <= low && endRange >= high)
        {
            segmentTree[pos] += delta;
            if(low != high)
            {
                lazy[2*pos + 1] += delta;
                lazy[2*pos + 2] += delta;
            }
            return;
        }
        int mid = (low + high)/2;
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,low,mid,2*pos + 1);
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,mid + 1,high,2 * pos + 2);
        segmentTree[pos] += Math.min(segmentTree[2*pos + 1],segmentTree[2*pos + 2]);
    }
    public int rangeMinimumQueryLazy(int[] segmentTree,int[] lazy,int qlow,int qhigh,int len)
    {
        return rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,0,len - 1,0);
    }
    private int rangeMinimumQueryLazy(int[] segmentTree,int[] lazy,int qlow,int qhigh,int low,int high,int pos)
    {
        if(low > high)
            return Integer.MAX_VALUE;
        if(lazy[pos] != 0)
        {
            segmentTree[pos] += lazy[pos];
            if(low != high)
            {
                lazy[2*pos + 1] += lazy[pos];
                lazy[2*pos + 2] += lazy[pos];
            }
            lazy[pos] = 0;
        }
        if(qlow > high || qhigh < low)
            return Integer.MAX_VALUE;
        if(qlow <= low && qhigh >= low)
            return segmentTree[pos];
        int mid = (low + high)/2;
        return Math.min(rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,low,mid,2*pos + 1),rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,mid + 1,high,2*pos + 2));
    }
}