//===================================================== file = prime1.c =====
//=  Program to find the first N prime numbers                              =
//===========================================================================

//----- Include files -------------------------------------------------------
#include <stdio.h>                 // Needed for printf() and feof()
#include <stdlib.h>                // Needed for atoi()
#include <math.h>                  // Needed for pow()

//===== Main program ========================================================
void main(int argc, char *argv[])
{
  unsigned int i, count, test_val, max, N;

  N = atoi(argv[1]);
  test_val = 3;
  count = 2;
  while(1)
  {
top:
    test_val = test_val + 2;
    max = sqrt((double) test_val) + 1;
    for (i=3; i<=max; i=i+2)
      if ((test_val % i) == 0) goto top;
    count++;
    if (count == N) break;
   }

   printf("The %dth prime number is %d \n", N, test_val);
}