Problem:
Score: 300 points

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

Solution in PyPy3 (7.3.0) (judge verdict: Accepted)

X = int(input())
lsx = [1]*(2*10**5)

for i in range(2,2*10**5):
    if lsx[i] == 1:
        for j in range(i,2*10**5//i):
            lsx[j*i] = 0

for i in range(X,2*10**5):
    if lsx[i] == 1:
        print(i)
        break