Difference of Big Integers

Given two integers $A$ and $B$, compute the difference, $A - B$.

Input

Two integers $A$ and $B$ separated by a space character are given in a line.

Output

Print the difference in a line.

Constraints

Sample Input 1

5 8

Sample Output 1

-3

Sample Input 2

100 25

Sample Output 2

75

Sample Input 3

-1 -1

Sample Output 3

0

Sample Input 4

12 -3

Sample Output 4

15