Conditional Sum

Background

Congcong is learning about number operations. He encountered an interesting summation problem that requires determining the final result based on the number of digits in the sum.

Problem Description

Given two non-negative integers $a$ and $b$, return their sum, so long as the sum has the same number of digits as $a$. If the sum has more digits than $a$, just return $a$ without $b$. (Note: one way to compute the number of digits of a non-negative integer $n$ is to convert it to a string with String.valueOf(n) and then check the length of the string.)

Input Format

Input is given from standard input in the following format.

$a$ $b$

Output Format

Output is printed to standard output in the following format.

[result]

Sample

2 3

5

8 3

8

8 1

9

Sample Explanation

Sample 1: $a=2, b=3$. $a+b=5$. $2$ has 1 digit, and $5$ also has 1 digit. The number of digits is the same, so return $5$. Sample 2: $a=8, b=3$. $a+b=11$. $8$ has 1 digit, but $11$ has 2 digits. The sum has more digits than $a$, so return $8$. Sample 3: $a=8, b=1$. $a+b=9$. $8$ has 1 digit, and $9$ also has 1 digit. The number of digits is the same, so return $9$.

Constraints

Time limit: 1 second, Memory limit: 1024 KiB for each test case.