Problem:
 Score : 100 points    Problem Statement There are H rows and W columns of white square cells.  You will choose h of the rows and w of the columns, and paint all of the cells contained in those rows or columns.  How many white cells will remain?  It can be proved that this count does not depend on what rows and columns are chosen.      Constraints  All values in input are integers.  1 \leq H, W \leq 20  1 \leq h \leq H  1 \leq w \leq W         Input Input is given from Standard Input in the following format:  H  W  h  w       Output Print the number of white cells that will remain.        Sample Input 1 3 2
2 1      Sample Output 1 1  There are 3 rows and 2 columns of cells. When two rows and one column are chosen and painted in black, there is always one white cell that remains.       Sample Input 2 5 5
2 3      Sample Output 2 6       Sample Input 3 2 4
2 4      Sample Output 3 0

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):


S = input().rstrip().split(' ')
s = input().rstrip().split(' ')

C = int(S[0])
c = int(s[0])
R = int(S[1])
r = int(s[1])

a = C*R - (r*C+(R-r)*c)

print(a)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
black=h*W+w*H-h*w
white=H*W-black
print(white)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H*W - (h*W+w*(H-h)))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):
H, W = [int(i) for i in input().split()]
h, w = [int(i) for i in input().split()]

print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split(' '))
h, w = map(int, input().split(' '))
print((H - h) * (W - w))

Solution (Python):
H,W = [ int(unko) for unko in input().split()]
h,w = [ int(unko) for unko in input().split()]
if 1 <= H and W <= 20:
    if 1 <= h <= H:
        if 1 <= w <= W:
            print((H * W) -  h * W - w * H + (h * w))

Solution (Python):
h,w = map(int,input().split())
hh,ww = map(int,input().split())
print(h*w-((hh*w)+(ww*h)-(hh*ww)))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H*W - h*W - w*H + h*w)

Solution (Python):
h0, w0= [int(i) for i in input().split(' ')]
h1, w1 = [int(i) for i in input().split(' ')]

print((h0 - h1)* (w0 - w1))

Solution (Python):
import numpy as np
H,W = map(int, input().split())
h,w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
import sys
input = sys.stdin.readline
H,W = map(int,input().rstrip().split())
h,w = map(int,input().rstrip().split())
cells = [[1]*W]*H
cells = cells[h:]
cells = list(zip(*cells))
cells = cells[w:]
print(sum(list(map(sum,list(zip(*cells))))))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print(int(H*W-h*W-H*w+h*w))

Solution (Python):
a,b=[int(i) for i in input().split()]
c,d=[int(i) for i in input().split()]
print((a-c)*(b-d))

Solution (Python):
H,W= map(int, input().split())
h,w= map(int, input().split())
ans= (H-h)*(W-w)
print(ans)

Solution (Python):
H, W = map(int, input().split())

h, w = map(int, input().split())

print((H - h) * (W- w))

Solution (Python):
white = list(map(int,input().split()))
black = list(map(int,input().split()))
print((white[0]-black[0])*(white[1]-black[1]))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
ans = (H-h)*(W-w)
print(ans)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H*W - (h*W + w*H - h*w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
ans = H * W - h * W - H * w + h * w
print(ans)

Solution (Python):
x,y = input().split(),input().split()
h,w,hh,ww = int(x[0]),int(x[1]),int(y[0]),int(y[1])
print((h - hh) * (w - ww))

Solution (Python):
H,W=[int(i) for i in input().split()]
h,w=[int(i) for i in input().split()]
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H * W - w * H - h * W + h * w)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print(H*W-H*w-h*W+h*w)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

answer = H*W - (H*w+W*h) + h*w

print(answer)

Solution (Python):
def main():
    H, W = map(int, input().split())
    h, w = map(int, input().split())
    print(H*W - (H*w + W*h - h*w))
main()

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
def solve(H, W, h, w):
    return (H - h) * (W - w)


def main():
    H, W = map(int, input().split())
    h, w = map(int, input().split())
    
    ans = solve(H, W, h, w)
    print(ans)
    

if __name__ == "__main__":
    main()

Solution (Python):
m=input().split()
n=input().split()
a=int(m[0])
b=int(m[1])
c=int(n[0])
d=int(n[1])
s=a*b
x=s-b*c-a*d+c*d
print(x)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

ret = (H * W) - (W * h) - (H * w) + (h * w)
print(ret)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H * W - (h * W + w * H - w * h))

Solution (Python):
H, W = [int(I) for I in input().split()]
h, w = [int(I) for I in input().split()]
print((H - h) * (W - w))

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
import numpy as np
H, W = (int(x) for x in input().split())
h, w = (int(x) for x in input().split())
board = np.tile([0],(H,W))

def Counting(b):
    ret = 0
    for i in range(H):
        for j in range(W):
            if b[i][j] == 0:
                ret += 1
    return ret

for i in range(h):
    for j in range(W):
        board[i][j] = 1
for j in range(w):
    for i in range(H):
        board[i][j] = 1

print(Counting(board))

Solution (Python):
H,W = list(map(int,input().split()))
h,w = list(map(int,input().split()))
print(H*W-h*W-H*w+h*w)

Solution (Python):
s = [input().split() for i in range(2)]
H = int(s[0][0])
W = int(s[0][1])
h = int(s[1][0])
w = int(s[1][1])
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H * W - h * W - w * H + h * w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H - h) * (W - w))

Solution (Python):
a=list(input().split())
b=list(input().split())
c=int(a[0])
d=int(a[1])
e=int(b[0])
f=int(b[1])
g=c*d-d*e-c*f+e*f
print(g)

Solution (Python):
H, W = map(int, input().split(' '))
h, w = map(int, input().split(' '))
print((H- h) * (W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

ans = (H-h)*(W-w)

print(ans)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
ans = 0

grid = [[0]*W for i in range(H)]

for i in range(h):
    grid.pop(0)
for j in range(w):
    for i in range(len(grid)):
        grid[i].pop(0)

for k in grid:
    ans += len(k)

print(ans)

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))
print((H-h)*(W-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
ah = h*W
aw = w*H-(h*w)
print(H*W-(ah+aw))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())



print((H-h)*(W-w))

Solution (Python):
def main():
	wh, ww = map(int, input().split())
	bh, bw = map(int, input().split())
	print((wh-bh)*(ww-bw))

if __name__ == '__main__':
    main()

Solution (Python):
import numpy as np
H, W = map(int, raw_input().split())
h, w = map(int, raw_input().split())

print int((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H * W - (h * W + w * (H - h)))

Solution (Python):
H,W,h,w=map(int,open(0).read().split())
print((W-w)*(H-h))

Solution (Python):
def is_int(s):
    try:
        i = int(s)
    except:
        return False
    return True

str = input().split()

if (len(str) > 2):
    print("Too many arguments.")
    exit()
elif (len(str) < 2):
    print("Too few arguments.")
    exit()
elif (not is_int(str[0])):
    print("H is not a number.")
    exit()
elif (not is_int(str[1])):
    print("W is not a number.")
    exit()

H = int(str[0])
W = int(str[1])

str = input().split()

if (len(str) > 2):
    print("Too many arguments.")
    exit()
elif (len(str) < 2):
    print("Too few arguments.")
    exit()
elif (not is_int(str[0])):
    print("h is not a number.")
    exit()
elif (not is_int(str[1])):
    print("w is not a number.")
    exit()

h = int(str[0])
w = int(str[1])

if (H < 1 or H > 20):
    print("Out of range at H.")
    exit()
elif (W < 1 or W > 20):
    print("Out of range at W.")
    exit()
elif (h < 1 or h > 20 or h > H):
    print("Out of range at h.")
    exit()
elif (w < 1 or w > 20 or w > W):
    print("Out of range at w.")
    exit()

print((H - h) * (W - w))

Solution (Python):
def main():
    H, W = map(int, input().split())
    h, w = map(int, input().split())
    black = h * W + H * w - h * w
    white = H * W
    after = white - black
    print(after)

main()

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h)*(W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h)*(W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h)*(W - w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
a=(H-h)*(W-w)
print(a)

Solution (Python):


H, W = map(int, input().split())
h, w = map(int, input().split())

print(H*W - (h*W + w*H - h*w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H - h) * (W - w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
A = H - h
B = W - w
print(int(A * B))

Solution (Python):
a,b=map(int,input().split())
c,d=map(int,input().split())
print((a-c)*(b-d))

Solution (Python):
a,b=map(int,input().split())
c,d=map(int,input().split())
print((a-c)*(b-d))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

ans = H*W - (h*W + w*H - h*w)
print(ans)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
def main():

    H, W = map(int, input().split())
    h, w = map(int, input().split())

    print((H-h)*(W-w))


main()

Solution (Python):

"""
A - White Cells
https://atcoder.jp/contests/abc121/tasks/abc121_a

"""
import sys


def main(args):
    H, W = map(int, input().split())
    h, w = map(int, input().split())
    ans = (H * W) - (H * w) - (W * h) + (w * h)
    print(ans)


if __name__ == '__main__':
    main(sys.argv[1:])

Solution (Python):
import sys
input = sys.stdin.readline

a,b = map(int,input().split())
h,w = map(int,input().split())
res = a*b-h*b-(a-h)*w
print(res)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
ans = 0

masu = [[0] * W for i in range(H)]

for i in range(h):
    for j in range(W):
        masu[i][j] = 1

for i in range(H):
    for j in range(w):
        masu[i][j] = 1

for i in range(H):
    for j in range(W):
        if masu[i][j] == 0:
            ans += 1

print(ans)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H * W - h * W - H * w + h * w)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())

U = H * W
black = h * W + w * H - h * w
print(U - black)

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
a = tuple(map(int, input().split()))
b = tuple(map(int, input().split()))
print((a[0]-b[0])*(a[1]-b[1]))

Solution (Python):
H,W=[int(i) for i in input().split()]
h,w=[int(i) for i in input().split()]
black = h*W + w*H - h*w
white = H*W - black
print(white)

Solution (Python):
N = list(map(int, input().split()))
n = list(map(int, input().split()))

print((N[0]-n[0])*(N[1]-n[1]))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):
def solve(string):
    h, w, _h, _w = map(int, string.split())
    return str((h - _h) * (w - _w))


if __name__ == '__main__':
    print(solve('\n'.join([input(), input()])))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
D=H*W
K=h*W+w*H-h*w
print(D-K)

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):

H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

total = H * W
black = W*h + H*w - h*w
ans = total - black
print (ans)

Solution (Python):
H,W=map(int, input().split())
h,w=map(int, input().split())
print((H-h)*(W-w))

Solution (Python):


H, W = map(int, input().split())
h, w = map(int, input().split())

print(W * H - (W * h + H * w - w * h))

Solution (Python):
def solve(H, W, h, w):
    return (H-h)*(W-w)

H, W = map(int, input().split())
h, w = map(int, input().split())
print(solve(H, W, h, w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(H*W - (h*W + w*H - h*w))

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())
print(H*W-h*W-w*H+h*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
 
x = H * W - ((H * w) + (W * h) - w * h)

print(x)

Solution (Python):


H, W = map(int, input().split())
h, w = map(int, input().split())

print((H - h) * (W - w))

Solution (Python):
n,m=map(int,input().split())
x,y=map(int,input().split())
print(n*m-x*m-y*(n-x))

Solution (Python):
import sys
input = sys.stdin.readline

H, W = map(int, input().split())
h, w = map(int, input().split())

print(H * W - h * W - w * H + h*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

b = h * W + w * (H - h)
print(H * W - b)

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())
 
print((H-h)*(W-w))

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())
 
print((H-h)*(W-w))

Solution (Python):
HW = list(map(int, input().split()))
hw = list(map(int, input().split()))
print((HW[0] - hw[0]) * (HW[1] - hw[1]))

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
A,B = map(int,input().split())
C,D = map(int,input().split())
print(abs(A-C)*abs(B-D))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h) * (W-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
block = H*W
print(block - h*W - (H-h)*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

white = H * W
bh = h * W
bw = w * H
bd = h * w

rest = white - bh - bw + bd

print(rest)

Solution (Python):
import sys

H, W = map(int, input().split())
h, w = map(int, input().split())

math_count = H * W
delete_math_count = (h * W) + (w * (H - h))

print(math_count - delete_math_count)

Solution (Python):
def main():
    H, W = map(int, input().split())
    h, w = map(int, input().split())
    print((H - h) * (W - w))


if __name__ == "__main__":
    main()

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())
print(H*W-(h*W+H*w-h*w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

masu = H * W
kuro = h*W + H*w - h*w

print(masu - kuro)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
x, y = map(int, input().split())

print(H*W-x*W-(H-x)*y)

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H,W = map(int, input().split(' '))
h,w = map(int, input().split(' '))
print((H-h)*(W-w))

Solution (Python):
g, r = map(int, input().split())
g_, r_ = map(int, input().split())
print((g * r) - (g * r_ ) - (g_ * r) + (g_ * r_))

Solution (Python):
h,w = map(int, input().split())
h1,w1 = map(int, input().split())
print((h-h1)*(w-w1))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = [int(i) for i in input().split()]
bh, bw = [int(i) for i in input().split()]

res = (H * W) - ((bh*W) + (bw*H) - (bh*bw))

print(res)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H*W-(w*H)-h*(W-w))

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))
 
print(int((H-h)*(W-w)))

Solution (Python):
hw = input().split()
h = int(hw[0])
w = int(hw[1])
hw_dis = input().split()
h_dis = int(hw_dis[0])
w_dis = int(hw_dis[1])
print(h*w-h_dis*w-w_dis*h+h_dis*w_dis)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print(H*W - W*h - (H-h)*w)

Solution (Python):
def main():
    H,W = (int(_) for _ in input().split())
    h,w = (int(_) for _ in input().split())

    print(H*W - h*W - w*H + h*w)

if __name__ == '__main__':
        main()

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))

print((H-h)*(W-w))

Solution (Python):
H, W = map(int,input().split())
h, w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
a, b = map(int, input().split())  
c, d = map(int, input().split())  



print(a*b - a*d - b*c + c*d)

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
a, b = map(int, input().split())
c, d = map(int, input().split())

print((a - c) * (b - d) )

Solution (Python):
H,W=(int(i) for i in input().split())
h,w=(int(i) for i in input().split())
 
print ((H-h)*(W-w))

Solution (Python):
import io, sys, atexit, os

import math as ma
from sys import exit
from decimal import Decimal as dec
from itertools import permutations


def li ():
	return list (map (int, input ().split ()))


def num ():
	return map (int, input ().split ())


def nu ():
	return int (input ())


def find_gcd ( x, y ):
	while (y):
		x, y = y, x % y
	return x


mm = 1000000007



def solve ():
	t = 1
	for it in range (t):
		a,b=num()
		c,d=num()
		ff=c*b+a*d-(c*d)
		print(a*b-ff)





if __name__ == "__main__":
	solve ()

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
output = (H-h)*(W-w)
print (output)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

total = H * W 
total -= h * W 
H -= h
total -= H * w
print(total)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

mass = H*W
delmass = h * W + w * (H-h)

print(mass-delmass)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print( (H-h) * (W-w) )

Solution (Python):


from pprint import pprint
from random import shuffle, sample

import numpy as np
import random

H, W = [int(x) for x in input().split(" ")]
h, w = [int(x) for x in input().split(" ")]

array = np.zeros((H, W), dtype=np.bool)

for r in sample(list(range(H)), h):
    array[r, :] = True

for c in sample(list(range(W)), w):
    array[:, c] = True

print(len(array[array == False]))

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))
print((H-h) * (W-w))

Solution (Python):
A,B=map(int,input().split())
C,D=map(int,input().split())
print((A-C)*(B-D))

Solution (Python):
A,B=map(int,input().split())
C,D=map(int,input().split())
print(A*B-(C*B+A*D-C*D))

Solution (Python):
H, W = input().split()
h, w = input().split()

H = int(H)
W = int(W)

h = int(h)
w = int(w)

S = (H-h)*(W-w)

print(S)

Solution (Python):
matrix = list(map(int,input().split()))
shitei = list(map(int,input().split()))

masume = matrix[0]*matrix[1]
black = shitei[0]*matrix[1]+shitei[1]*(matrix[0]-shitei[0])
white = masume-black

print(white)

Solution (Python):
from math import *



h,k=map(int,input().split(" "))
a,b=map(int,input().split(" "))

print((h*k)-(a*k)-(b*h)+(a*b))

Solution (Python):


H,W = map(int,input().split())
h,w = map(int,input().split())

print(H*W-h*W-H*w+h*w)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split()) 
print((H-h)*(W-w))

Solution (Python):


H,W=input().split(" ")
h,w=input().split(" ")
H=int(H)
W=int(W)
h=int(h)
w=int(w)

print(H*W-H*w-h*W+h*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):
H,W = list(map(int,input().split()))
h,w = list(map(int,input().split()))
print((H-h)*(W-w))

Solution (Python):
H,W=input().split()
h,w=input().split()

x=int(H)-int(h)
y=int(W)-int(w)
print(x*y)

Solution (Python):
H,W=input().split()
h,w=input().split()

a=int(H)-int(h)
b=int(W)-int(w)
print(a*b)

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))

print((H-h)*(W-w))

Solution (Python):
input1 = input().split()
input2 = input().split()

W = int(input1[0])
w = int(input2[0])
H = int(input1[1])
h = int(input2[1])

print(str((W-w)*(H-h)))

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))
 
print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print(int(H*W - h*W - H*w + h*w))

Solution (Python):
line, row = map(int,input().split())
line_marker, row_marker = map(int, input().split())
line -= line_marker
row -= row_marker
print(line * row)

Solution (Python):
h_all, w_all = map(int, input().split())
h_b, w_b = map(int, input().split())
 
print((h_all - h_b) * (w_all - w_b))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
sum=H*W-H*w-W*h+w*h
print(sum)

Solution (Python):
H,W=map(int,input().split(" "))
h,w=map(int,input().split(" "))

print((H-h)*(W-w))

Solution (Python):
H,W=map(int,input().split(" "))
h,w=map(int,input().split(" "))






print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):


H, W = input().split()
h, w = input().split()

ans = ( int(H)-int(h) ) * ( int(W)-int(w) )
print(ans)

Solution (Python):
r, c = map(int, input().split())
h, w = map(int, input().split())
print(r*c - (h*c + w*r - h*w))

Solution (Python):
from sys import stdin

H, W = [int(x) for x in stdin.readline().rstrip().split()]


h, w = [int(x) for x in stdin.readline().rstrip().split()]

white_cell = H * W

black_cell = h * W + w * H - h * w

print(white_cell - black_cell)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h) * (W-w))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))
print((H - h) * (W - w))

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))

print((H-h)*(W-w))

Solution (Python):
matrix = input().split(" ")
select = input().split(" ")
ans = 0
x = int(matrix[0]) - int(select[0])
y = int(matrix[1]) - int(select[1])
ans = x * y
print(ans)

Solution (Python):
inpl = lambda: list(map(int,input().split()))
H,W = inpl()
h,w = inpl()
print((H-h)*(W-w))

Solution (Python):
inpl = lambda: list(map(int,input().split()))
H,W = inpl()
h,w = inpl()
print((H-h)*(W-w))

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())

a = (H-h) * (W-w)

print(a)

Solution (Python):
x,y=map(int,input().split())
a,b=map(int,input().split())
print((x-a)*(y-b))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
white_cell = H * W

white_cell -= h * W

white_cell -= (H - h) * w

print(white_cell)

Solution (Python):
K,W = [int(x) for x in input().split()]
h,w = [int(x) for x in input().split()]
print ((K-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

res = (H-h)*(W-w)

print(res)

Solution (Python):


num1 = input().split()
num2 = input().split()

H = int(num1[0])
W = int(num1[1])
h = int(num2[0])
w = int(num2[1])

total = (H - h) * (W - w)

print(total)

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())
print((H - h) * (W - w))

Solution (Python):

H, W = map(int, input().split())
h, w = map(int, input().split())

N_black = h * W + H * w - h * w
N_white = H * W - N_black

print(N_white)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H - h) * (W - w))

Solution (Python):
i = list()
for x in range(2):
  i.append([int(x) for x in input().split()])
print((i[0][0]-i[1][0])*(i[0][1]-i[1][1]))

Solution (Python):
H,W=(int(x) for x in input().split())
h,w=(int(x) for x in input().split())

print((H-h) * (W-w))

Solution (Python):
"""White Cells"""
H,W=(int(i) for i in input().split())
h,w=(int(i) for i in input().split())
print(H*W-H*w-W*h+h*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
remained_mas = H * W - h * W - w * H + h * w
print(remained_mas)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H*W-h*W-w*H+h*w)

Solution (Python):
H,W = map(int, input().split(' '))
h,w = map(int, input().split(' '))

print((H-h) * (W-w))

Solution (Python):

H,W = list(map(int,input().split()))
h,w = list(map(int,input().split()))

print((H-h) * (W-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print(W*H - h*W - w*(H-h))

Solution (Python):

import sys


def solve(H: int, W: int, h: int, w: int):
    ret = (H - h) * (W - w)
    print(ret)
    return


def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    H = int(next(tokens))  
    W = int(next(tokens))  
    h = int(next(tokens))  
    w = int(next(tokens))  
    solve(H, W, h, w)

if __name__ == '__main__':
    main()

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):

H,W = map(int, input().split())
h,w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):

H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h)*(W-w))

Solution (Python):
a,b = map(int,input().split())

h,w = map(int,input().split())

print((a-h)*(b-w))

Solution (Python):
a,b = map(int,input().split())

h,w = map(int,input().split())

print((a-h)*(b-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
ans = (H-h)*(W-w)
print(ans)

Solution (Python):
input_line = input()
temp = input_line.split()
H, W = int(temp[0]), int(temp[1])
input_line = input()
temp = input_line.split()
h, w = int(temp[0]), int(temp[1])

field = H*W
colored = h*W + w*H - w*h

print(field - colored)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H-h) * (W-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
import sys

H, W = map(int, sys.stdin.readline().split())
h, w = map(int, sys.stdin.readline().split())
print((H - h) * (W - w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print(H * W - h * W - w * H + h * w)

Solution (Python):
N,M=map(int,input().split())
A,B=map(int,input().split())
X=(N-A)*(M-B)
print(X)

Solution (Python):
H, W = list(map(int, input().split()))
h, w = list(map(int, input().split()))

white = H*W
black = h*W + w*(H-h)

print(white-black)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

print((H - h)*(W - w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print((H-h)*(W-w))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print("{}".format(H*W-h*W-w*H+h*w))

Solution (Python):
n = [input().split() for i in range(2)]
H = int(n[0][0])
W = int(n[0][1])
h = int(n[1][0])
w = int(n[1][1])
answer = H*W-h*W-w*H+h*w
print(answer)

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())

print((H*W + h*w) - (H*w + W*h))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print((H-h)*(W-w))

Solution (Python):


import numpy as np

INPUT=input().split()
Input=input().split()
H,W=int(INPUT[0]),int(INPUT[1])
h,w=int(Input[0]),int(Input[1])

mat=np.ones((H,W))
mat[0:h,:]=0
mat[:,0:w]=0

print(int(np.sum(mat)))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
a = (H-h) * (W-w)
print(a)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())

ans = (H - h) * (W - w)

print(ans)

Solution (Python):
H,W = map(int, input().split())
h,w = map(int, input().split())
print(H*W-h*W-(H-h)*w)

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
print((H-h)*(W-w))

Solution (Python):
H, W = [int(s) for s in input().split()]
h, w = [int(s) for s in input().split()]
print((H-h)*(W-w))

Solution (Python):
h,w=map(int,input().split())
h1,w1=map(int,input().split())
ans=h*w
ans=ans-(h1*w)
ans=ans-(w1*(h-h1))
print((ans))

Solution (Python):
H,W=map(int,input().split())
h,w=map(int,input().split())
print((H-h)*(W-w))

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
print(H*W - h*W - H*w + h*w)

Solution (Python):
m, n = list(map(int, input().split()))
a, b = list(map(int, input().split()))


print((m - a) * (n - b))

Solution (Python):
bigH, bigW = map(int, input().split())
smallH, smallW = map(int, input().split())

print((bigH-smallH)*(bigW-smallW))

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
num_black = h*W + w*(H-h)
print(H*W - num_black)