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).
#!/usr/bin/env python
from __future__ import division, print_function
import math
import os
import sys
from fractions import *
from sys import stdin,stdout
from io import BytesIO, IOBase
from itertools import accumulate
from collections import deque
#sys.setrecursionlimit(10**5)

def inp(): return sys.stdin.readline().rstrip("\r\n")  # for fast input

def out(var): sys.stdout.write(str(var))  # for fast output, always take string

def lis(): return list(map(int, inp().split()))

def stringlis(): return list(map(str, inp().split()))

def sep(): return map(int, inp().split())

def strsep(): return map(str, inp().split())

def fsep(): return map(float, inp().split())

def inpu(): return int(inp())

if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip
#sys.setrecursionlimit(10**6)

# region fastio

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", "\n"))
    if kwargs.pop("flush", False):
        file.flush()


if sys.version_info[0] < 3:
    sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
    sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)

input = lambda: sys.stdin.readline().rstrip("\r\n")
#-----------------------------------------------------------------

def regularbracket(t):
    p=0
    for i in t:
        if i=="(":
            p+=1
        else:
            p-=1
        if p<0:
            return False
    else:
        if p>0:
            return False
        else:
            return True

#-------------------------------------------------
def binarySearchCount(arr, n, key):
    left = 0
    right = n - 1

    count = 0

    while (left <= right):
        mid = int((right + left) / 2)

        # Check if middle element is
        # less than or equal to key
        if (arr[mid] <= key):
            count = mid+1
            left = mid + 1

        # If key is smaller, ignore right half
        else:
            right = mid - 1
    return count
#------------------------------reverse string(pallindrome)
def reverse1(string):
    pp=""
    for i in string[::-1]:
        pp+=i
    if pp==string:
        return True
    return False
#--------------------------------reverse list(paindrome)
def reverse2(list1):
    l=[]
    for i in list1[::-1]:
        l.append(i)
    if l==list1:
        return True
    return False
def mex(list1):
    #list1 = sorted(list1)
    p = max(list1)+1
    for i in range(len(list1)):
        if list1[i]!=i:
            p = i
            break
    return p
def sumofdigits(n):
    n = str(n)
    s1=0
    for i in n:
        s1+=int(i)
    return s1
def perfect_square(n):
    s = math.sqrt(n)
    if s==int(s):
        return True
    return False

#-----------------------------roman
def roman_number(x):
    if x>15999:
        return
    value=[5000,4000,1000,900,500,400,100,90,50,40,10,9,5,4,1]
    symbol = ["F","MF","M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"]
    roman=""
    i=0
    while x>0:
        div = x//value[i]
        x = x%value[i]
        while div:
            roman+=symbol[i]
            div-=1
        i+=1
    return roman

def soretd(s):
    for i in range(1,len(s)):
        if s[i-1]>s[i]:
            return False
    return True
#print(soretd("1"))
#---------------------------
def countRhombi(h, w):
    ct = 0
    for i in range(2, h + 1, 2):
        for j in range(2, w + 1, 2):
            ct += (h - i + 1) * (w - j + 1)
    return ct
def countrhombi2(h,w):
    return ((h*h)//4) * ((w*w)//4)
#---------------------------------
def binpow(a,b):
    if b==0:
        return 1
    else:
        res=binpow(a,b//2)
    if b%2!=0:
        return res*res*a
    else:
        return res*res
#-------------------------------------------------------
def binpowmodulus(a,b,m):
    a %= m
    res = 1
    while (b > 0):
        if (b & 1):
            res = res * a % m
        a = a * a % m
        b >>= 1
    return res
#-------------------------------------------------------------
def coprime_to_n(n):
    result = n
    i=2
    while(i*i<=n):
        if (n % i == 0):
            while (n % i == 0):
                n //= i
            result -= result // i
        i+=1
    if (n > 1):
        result -= result // n
    return result
#-------------------prime
def prime(x):
    if x==1:
        return False
    else:
        for i in range(2,int(math.sqrt(x))+1):
            if(x%i==0):
                return False
        else:
            return True

def luckynumwithequalnumberoffourandseven(x,n,a):
    if x >= n and str(x).count("4") == str(x).count("7"):
        a.append(x)
    else:
        if x < 1e12:
            luckynumwithequalnumberoffourandseven(x * 10 + 4,n,a)
            luckynumwithequalnumberoffourandseven(x * 10 + 7,n,a)
    return a

#def mapu(): return map(int,input().split())
#endregion------------------------------
"""
def main():
    x,y,n = sep()

    c = (Fraction(x,y).limit_denominator(n))
   # print(type(c))
   # print(c)
    c = str(c)
    if "/" in c:
            print(c)
    else:
            print(c+"/"+"1")

if __name__ == '__main__':
    main()
"""
"""
if __name__ == '__main__':
    a,b = sep()
    print(countRhombi(a,b))
"""
"""
def main():
    m = inpu()
    l=[0]*5
    for _ in range(m):
        a,b = sep()
        l[a - 1] += 1
        l[b - 1] += 1
    #print(l)
    if l.count(2) == 5:
        print('FAIL')
    else:
            print('WIN')
if __name__ == '__main__':
    main()
"""
h,w = sep()
print(countrhombi2(h,w))