#include<stdio.h>

#define PRIMENUM 100000

void PrimeNum(unsigned int a[], unsigned int UserInput); /* Function prototype */

int main(void)
{
     unsigned int i, UserInput;
     unsigned int j = 0;
     unsigned int a[PRIMENUM];
     unsigned int b[PRIMENUM];
     printf(" Enter a Number:" );
     scanf( "%d", &UserInput);
     while(getchar()!='\n');

     if ( UserInput <=0 )

         {
            printf(" Invalid input, please type a postive non zero number:" );
            scanf( "%d", &UserInput);
            while(getchar()!='\n');
         }

     for (i = 0;i < PRIMENUM; i++)/*filss the array with elements*/
          a[i] = 2 + i;           /* 2,3,4,.., 100000 */

     PrimeNum(a, UserInput);
     for ( i = 0; i <= UserInput && i < PRIMENUM; i++)
         printf(" %d ", a[i]  );

     getchar();
     getchar();
    
     return 0;
}

/*Function void Prime_Num(int num[]) finds the prime integers */
void PrimeNum(unsigned int a[], unsigned int UserInput)
{
     unsigned int i;
     unsigned int j;

     for(i = 0; i <= UserInput && i < PRIMENUM; i++) /*loops through to find the prime integers for the rest of the array*/
     {
          if(a[i]!=0)
          {
               for(j = i + 1; j < PRIMENUM; j++)
               {
                    if(a[j]!= 0)
                    {
                         if((a[j] % a[i])== 0)  /*check if a[j]*/
                         a[j] = 0;                /*is a multiple of a[i]*/
                                                /*if it is a multiple then strike it out*/
                    }
               }
          }
        
}
  /* now i need to copy the nonzero elements of a[] to b[]*/
}