#include <msvcrt/ctype.h>
#include <msvcrt/stdlib.h>

/*
 * @implemented
 */
__int64
_atoi64(const char *nptr)
{
  char *s = (char *)nptr;
  __int64 acc = 0;
  int neg = 0;

  while(isspace((int)*s))
    s++;
  if (*s == '-')
    {
      neg = 1;
      s++;
    }
  else if (*s == '+')
    s++;

  while (isdigit((int)*s))
    {
      acc = 10 * acc + ((int)*s - '0');
      s++;
    }

  if (neg)
    acc *= -1;
  return acc;
}