206 - Subtraction Sum

Subtraction Sum

Time Limit: 1 sec


The Problem

Make a simple program that reads four variables named mn, o, p. Calculate and print the sum of subtraction of mn and subtraction of op.



The Input

The input file contains 4 integer numbers m, n, o, and p (m<1000, n<1000, o<1000 and p<1000).


The Output

Output will show the SUM of m - n and o - p in a separate line.


Sample Input

10 4 5 2


Sample Output






Problem Setter: Nezam Uddin