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

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

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

    sum1 = a-c
    sum2 = b-d

    ans = sum1*sum2

    print(ans)


if __name__ == "__main__":
    main()

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

total = A * B 
black = (a * B + b * A) - (a * b) 

ans = total - black

print(str(ans))

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())
a, b = map(int, input().split())

total = A * B 
black = (a * B + b * A) - (a * b) 

ans = total - black

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

Solution (Python):
H, W = map(int, input().split())
h, w = map(int, input().split())
left = H*W
for i in range(h):
    left -= W
for i in range(w):
    if left <= 0:
        left = 0
    else:
        left -= H-h
print(left)

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


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())

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

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

Solution (Python):
H,W=(map(int,input().split()))
h,w=(map(int,input().split()))
b=0
b=(H-h)*(W-w)
print(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*W - H*w - h*W + h*w)

Solution (Python):
import sys
import os


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

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

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

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


if __name__ == '__main__':
    solve()

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

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):
A,B=map(int,input().split())
h,w=map(int,input().split())
print(A*B-A*w-B*h+h*w)

Solution (Python):

import sys


def solve(H: int, W: int, h: int, w: int):
    print ((H-h)*(W-w))
    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 = list(map(int, input().split()))
h, w = list(map(int, input().split()))
t, hw, ans = 0, 0, 0
hw = h * w
t = H * W
print(t + hw - h * W - w * H)

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

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

Solution (Python):
stdin = input().split(" ")
stdin2 = input().split(" ")

Hh = int(stdin2[0]) - int(stdin[0])
Ww = int(stdin2[1]) - int(stdin[1])
print(Hh * Ww)

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())
H -= h
W -= w
print(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):
import numpy as np


H, W = map(int, input().split())
h, w = map(int, input().split())
table = np.array([[0 for i in range(W)] for j in range(H)])
ans = 0
for i in range(h):
    table[i] += 1
for i in range(H):
    table[i][:w] += 1
    ans += sum(table[i])
print((H*W)-(ans-(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()))
[X,Y] = list(map(int,input().split()))
print((H-X)*(W-Y))

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

Solution (Python):



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

s = H*W

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

print(s)

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

Solution (Python):

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

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

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

Solution (Python):
H,W = map(int,input().split())
h,w = map(int,input().split())
dp = [["W" for i in range(H)] for i in range(W)]
sums = H*W
ans = sums - (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):
h, w = map(int, input().split())
a, b = map(int, input().split())
print((h-a) * (w-b))

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

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

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 - (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())
h0,w0=map(int,input().split())
print((h-h0)*(w-w0))

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

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

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

Solution (Python):



H, W = [int(x) for x in input().split()]
h, w = [int(x) for x in input().split()]
print(H * W - (h * W + w * H - h * w))

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

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

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

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

    print(total)

if __name__ == '__main__':
    main()

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

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

print(H*W-paint)

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

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

Solution (Python):


H, W = map(int, input().split())
sh, sw = map(int, input().split())

print((H*W) - ((H*sw) + (W*sh) - (sw*sh)))

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

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

Solution (Python):
import sys
 
stdin = sys.stdin
 
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nan = lambda x: [na() for _ in range(x)]
ns = lambda: stdin.readline().rstrip()
nas = lambda: stdin.readline().split()

h, w = na()
a, b = na()
c, d = a * w, b * (h - a)
print((h * w) - (c + d))

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

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

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):
h1,w1 = list(map(int,input().split()))
h2,w2 = list(map(int,input().split()))

ans = h1*w1 - h2*w1 - h1*w2 + h2*w2
print(ans)

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


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())

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 = 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 * 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):
def main(H,W,h,w):
    return (H-h)*(W-w)

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

print(main(H,W,h,w))

Solution (Python):
import sys
def input(): return sys.stdin.readline().rstrip()

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

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

Solution (Python):
import sys

INPUT = lambda: sys.stdin.readline().rstrip()
MAP = lambda: map(int, INPUT().split())

sys.setrecursionlimit(10 ** 9)


def main():
    H, W = MAP()
    h, w = MAP()
    print((H - h)*(W - w))


if __name__ == '__main__':
    main()

Solution (Python):

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

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

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

Solution (Python):
HW=list(map(int,input().split()))
hw=list(map(int,input().split()))
ans=HW[0]*HW[1]
b=hw[0]*HW[1]+hw[1]*HW[0]-hw[0]*hw[1]
ans-=b
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):
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())
print(H*W - w*H - W*h + w*h)

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):
row, col = map(int, input().split())
hei, wid = map(int, input().split())
print((row-hei)*(col-wid))

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())
x, y = map(int, input().split())
print((h-x)*(w-y))

Solution (Python):
import sys
import math
import itertools

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

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 = map(int, input().split())
h, w = map(int, input().split())
print(max(H-h,0)*max(W-w,0))

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

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

Solution (Python):
a, b = (int(i) for i in input().split())
c, d = (int(i) for i in input().split())

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

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())

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

Solution (Python):
l = input().split(" ")
s = input().split(" ")

H = int(l[0])
W = int(l[1])
h = int(s[0])
w = int(s[1])

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

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

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

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

Solution (Python):
H, W = map(int, raw_input().split())
h, w = map(int, raw_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 = h * W + w * (H - h)
ans = total - black

print(ans)

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


if __name__ == '__main__':
    main()

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):
"""
author : halo2halo
date : 15, Jan, 2020
"""

import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

H, W, h, w = map(int, read().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):
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):
import sys
input = sys.stdin.readline

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):
import sys

H, W, h, w = map(int, sys.stdin.read().split())

def main():
    return H * W - (h * W + w * H - h * w)

if __name__ == '__main__':
    ans = main()
    print(ans)

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())
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())

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

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):
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())

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

Solution (Python):
rh,rw = map(int,input().split())
ch,cw = map(int,input().split())

print(rh*rw-(rw*ch+(rh-ch)*cw))

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

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

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):
import numpy as np
a, b = map(int, input().split())
c, d = map(int, input().split())
x = (np.array([a, b]) - np.array([c, d]))
print(x[0]*x[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())
a,b=map(int,input().split())
print((A*B)-(a*b+(A-a)*b+(B-b)*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())

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
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
def input():
    return sys.stdin.readline().rstrip()

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

if __name__ == '__main__':
    main()

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

Solution (Python):
INT = lambda: int(input())
INTM = lambda: map(int,input().split())
STRM = lambda: map(str,input().split())
STR = lambda: str(input())
LIST = lambda: list(map(int,input().split()))
LISTS = lambda: list(map(str,input().split()))
def do():
    H,W=INTM()
    h,w=INTM()
    print(H*W-H*w-h*W+h*w)
if __name__ == '__main__':
    do()

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):
p=[list(map(int,input().split())) for i in range(2)]

print((p[0][0]-p[1][0])*(p[0][1]-p[1][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*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())
r,c = map(int,input().split())

import numpy as np

matrix = np.ones((H,W),dtype="uint8")
matrix[0:r,:] = 0
matrix[:,0:c] = 0
print(matrix.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*W - (H*w + 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())
ch, wh = map(int, input().split())

ans = 0
for i in range(h-ch):
    for j in range(w-wh):
            ans += 1
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*W-(h*W+w*H-h*w))

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

Solution (Python):
H,W = map(int, input().split())
h1,w1 = map(int, input().split())
sum = H-h1
sum1 = W-w1


print(sum*sum1)

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

Solution (Python):
import bisect
import cmath
import heapq
import itertools
import math
import operator
import os
import re
import string
import sys
from collections import Counter, deque, defaultdict
from copy import deepcopy
from decimal import Decimal
from fractions import gcd
from functools import lru_cache, reduce
from operator import itemgetter, mul, add, xor

import numpy as np

if os.getenv("LOCAL"):
    sys.stdin = open("_in.txt", "r")

sys.setrecursionlimit(10 ** 9)
INF = float("inf")
IINF = 10 ** 18
MOD = 10 ** 9 + 7



a, b = list(map(int, sys.stdin.buffer.readline().split()))
c, d = list(map(int, sys.stdin.buffer.readline().split()))
print((a -c ) * (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())
print((H*W)-((h*W)+(w*H)-(h*w)))