/* A program that prints all primes smaller than a number */

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

int main()
{
  int i, j, sq, last;
  printf("Enetr a number: ");
  if (scanf("%d", &last) != 1) {
    printf("ERROR: failed to read a number!\n");
    return -1;
  }
  for (i = 2; i <= last; i++) {
    sq = (int) sqrt(i);
    for (j = 2 ; j <= sq; j++)
      if (i % j == 0)
        break;
    if (j > sq) 	
      printf("the number %d is prime\n", i);  
  }
  return 0;
}