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>
#include<string.h>
int main(void)
{
    long long int a,b,k;
    scanf("%lld%lld%lld",&a,&b,&k);

    if(k>=a+b)
    {
        a=0;
        b=0;
    }
    else if(k>a)
    {
        b-=(k-a);
        a=0;
    }
    else if(k<=a)
    {
        a-=k;
    }
    printf("%lld %lld",a,b);
    return 0;
}