Rectangular Area.py

##You are given a rectangle in a plane. The corner coordinates of this rectangle is provided to you. You have to print the amount of area of the plane covered by this rectangles.
##The end coordinates are provided as four integral values: x1, y1, x2, y2. It is given that x1 < x2 and y1 < y2.



# Write your code here
x1=int(input())
y1=int(input())
x2=int(input())
y2=int(input())
print((x2-x1)*(y2-y1))