Big Integer Subtraction

Problem Background

Special for beginners, ^_^

Problem Description

Compute the difference of two large positive integers.

Input Format

Two lines in total: the first line is the minuend $a$, the second line is the subtrahend $b$ ($a > b$). Each large integer has no more than $200$ digits and no extra leading zeros.

Output Format

One line: the difference.

Sample Input 1

9999999999999999999999999999999999999
9999999999999

Sample Output 1

9999999999999999999999990000000000000

Constraints

1s, 1024KiB for each test case.