**Time limit:**1.00 s**Memory limit:**512 MB

**Input**

The only input line has two integers $a$ and $b$.

**Output**

Print one integer: the answer to the problem.

**Constraints**

- $0 \le a \le b \le 10^{18}$

**Example**

Input:

`123 321`

Output:

`171`

**Time limit:**1.00 s**Memory limit:**512 MB

The only input line has two integers $a$ and $b$.

Print one integer: the answer to the problem.

- $0 \le a \le b \le 10^{18}$

Input:

`123 321`

Output:

`171`