Subtraction Sum

Time Limit: 1 sec

 

The Problem

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

 

 

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

 9

 

 

 

 

Problem Setter: Nezam Uddin