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 C (GCC 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
int sosuu(int a)
{
  int k,sw;
  k=0;
  for(int i=2;i<a/2;++i)
  {
  if(a%i==0) {k++;}
  }
  if(k>0) sw=1;
  else sw=0;
return sw;
}
int main()
{
int n,cc;
  cc=0;
  scanf("%d",&n);
  
  while(cc==0)
  {
  if(sosuu(n)==0) cc++;
  else n++;
  }
  printf("%d",n);
return 0;}