/* get next integer from input into *pn */
int getint(int *pn) {
     int c, t, sign;

     while (isspace(c = getch()));
     if (!isdigit(c) && c != EOF && c != '+' && c != '-') {
	  ungetch(c);
	  return 0;
     }
     sign = (c == '-') ? -1 : 1;
     if (c == '+' || c == '-') {
	  t = c;
	  if (!isdigit(c = getch())) {
	       ungetch(c);
	       ungetch(t);
	       return t;
	  }
     }
     for (*pn = 0; isdigit(c); c = getch())
	  *pn = 10 * *pn + (c - '0');
     *pn *= sign;
     if (c != EOF)
	  ungetch(c);
     return c;
}

/* get next float from input into *pn */
int getfloat(float *pn) {
     int c, t, sign, pow;

     while (isspace(c = getch()));
     if (!isdigit(c) && c != EOF && c != '+' && c != '-' && c != '.') {
	  ungetch(c);
	  return 0;
     }
     sign = (c == '-') ? -1 : 1;
     if (c == '+' || c == '-') {
	  t = c;
	  if (!isdigit(c = getch())) {
	       if (c != '.') {
		    ungetch(c);
		    ungetch(t);
		    return t;
	       }
	  }
     }
     for (*pn = 0; isdigit(c); c = getch())
	  *pn = 10 * *pn + (c - '0');
     if (c == '.') 
	  c = getch();
     for (pow = 1; isdigit(c); c = getch(), pow *= 10)
	       *pn = 10 * *pn + (c - '0');
     *pn *= sign;
     *pn /= pow;
     if (c != EOF)
	  ungetch(c);
     return c;
}