101492: [AtCoder]ABC149 C - Next Prime

Problem Statement

Find the minimum prime number greater than or equal to $X$.

Notes

A prime number is an integer greater than $1$ that cannot be evenly divided by any positive integer except $1$ and itself.

For example, $2$, $3$, and $5$ are prime numbers, while $4$ and $6$ are not.

Constraints

• $ 2 \le X \le 10^5 $
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

$X$

Output

Print the minimum prime number greater than or equal to $X$.

Sample Input 1

20

Sample Output 1

23

The minimum prime number greater than or equal to $20$ is $23$.

Sample Input 2

2

Sample Output 2

2

$X$ itself can be a prime number.

Sample Input 3

99992

Sample Output 3

100003