#include <stdlib.h> /* C standard library */
#include <unistd.h> /* unix standard library */
#include <string.h> /* C strings library */
-#include <limits.h>
+#include <limits.h> /* system limits constants, types and functions */
#include <stdio.h> /* standard I/O library */
#include <time.h> /* date and time constants, types and functions */