#include <stdio.h>

#define bool int

  

/* Returns 1 if n is a lucky no. ohterwise returns 0*/

bool isLucky(int n)

{

    static int counter = 2;

      

    /*variable next_position is just for readability of the program we can remove it and use n only */

    int next_position = n;

    if(counter > n)

        return 1;

    if(n%counter == 0)

        return 0;     

      

    /*calculate next position of input no*/

    next_position -= next_position/counter;

      

    counter++;

    return isLucky(next_position);

}

  

/*Driver function to test above function*/

int main()

{

    int x = 5;

    if( isLucky(x) )

        printf("%d is a lucky no.", x);

    else

        printf("%d is not a lucky no.", x);

    getchar();

}