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 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
 
int main(void){
  int N;
  int i;
  
  scanf("%d",&N);
  
  if(N % 2 != 0 && N % 3 != 0 && N % 5 != 0 && N % 7 != 0){
    printf("%d\n",N);
  } else {
    for(i=N+1;i<10000;i++){
      if(i % 2 != 0 && i % 3 != 0 && i % 5 != 0 && i % 7 != 0)
        break;
    }
    printf("%d\n",i);
  }
  
  return 0;
}