Pond Digging (II)
Time Limit: 1 sec
You all may be remembered Mrs. Rahman who wanted to dig a pond in her rectangular plot. After talking Ali suddenly a thought came to her mind what will be the area of the edge. She made a way to calculate this. Can you find the way which she used to calculate the area of edge?
The input file contains four integer numbers length, L (L<=500) and width, W (W<=400) of the plot and length, l (l<=5) and width, w (W<=4) of the border.
The output will show the area of the edge in a separate line.
100 80 3 2
Problem Setter: Samia Safa Ahmed
Special thanks to Shahin ShamS