#include <stdio.h>
#include <math.h>

#define n 1000
int prime(int);
FILE *output;                   /* internal filename */
main()
{
  int i,j,k,COUNTER;

output=fopen("p1.dat", "w"); /* external filename */
printf("enter a number\n");
 scanf("%d", &k);
 COUNTER=0;
    for(i=k/2;i<=(3*(k/2));i++)
    {
        if(prime(i)!=0)
                {
                fprintf (output, "%d\t", i);
		COUNTER++;
                }
	else{}
   

    }
    fclose(output);
    printf("%d\n",COUNTER);
 }

 int prime(int i)
 {
 int j,k;
 j=2;
 while(j<10)
 {

   k=0;
   
     if(i==j)
       {
	 k=0;
	
       }
     else{}
       
     if(fmod(i,j)==0)
	   {
                       k=0;
                       j=100;
	   }
	 else
	   {
	     k=1;
	     j++;
		
	   }
 }  
  return k;
 
}