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 (2.4.0) (judge verdict: Accepted)

import math 
n=int(input())
f=0
if(n==2):
    print(2)
else:
    if(n%2==0):
        n=n+1
    while(f==0):
        k=math.sqrt(n)
        k=math.ceil(n)
        l=0
        for i in range(2,k):
            if(n%i==0):
                break
            else:
                l=l+1
        if(l==k-2):
            f=1
            print(n)
        else: 
            n=n+2