#include <stdio.h>
#include "4_3_getch.h"
#define BUFSIZE 100

char buf[BUFSIZE];
int bufp = 0;

int getch(void) { return (bufp > 0) ? buf[--bufp] : getchar(); }

void ungetch(int c) {
  if (bufp >= BUFSIZE)
    printf("ungetch: too many charachters\n");
  else
    buf[bufp++] = c;
}