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

#define MAXOP 100
#define NUMBER '0'
#define MAXVAL 100
#define BUFSIZE 100
#define MAXLINE 1000

int getop(char []);
int getsop(char [], char []);
void push(double);
double pop(void);
int getch(void);
void ungetch(int);
int getline(char *, int);

int sp = 0;
double val[MAXVAL];
int buf[BUFSIZE];
int bufp = 0;
double p;
float vars[26];

int isnum(char *s) {

     if (*s == '+' || *s == '-' || *s == '.')
	  s++;
     if (isdigit(*s))
	  return 1;
     
     return 0;
}

int main(int argc, char *argv[]) {
     int type;
     double op2;
     char s[MAXOP];
     char line[MAXLINE] = "\0";

     while (--argc > 0) {
	  argv++;
	  if (isnum(argv[0])) {
	       push(atof(argv[0]));
	  } else switch (*argv[0]) {
	  case '+':
	       push(pop() + pop());
	       break;
	  case '-':
	       push(pop() - pop());
	       break;
	  case '*':
	       push(pop() * pop());
	       break;
	  case '/':
	       op2 = pop();
	       if (op2 != 0.0)
		    push(pop() / op2);
	       else
		    printf("error: zero divisor\n");
	       break;
	  case '%':
	       op2 = pop();
	       if (op2 != 0.0)
		    push(fmod(pop(), op2));
	       else
		    printf("error zero divisor\n");
	       break;
	  default:
	       printf("error: unknown shit: %s\n", argv[0]);
	       break;
	  }
     }

     printf("\t%.8g\n", pop());
     return 0;
}

void push(double f) {
     
     if (sp < MAXVAL) {
	  val[sp++] = f;
	  p = f;
     } else
	  printf("error: stack full, can't push %g\n", f);
}

double pop(void) {
     
     if (sp > 0)
	  return val[--sp];
     else {
	  printf("error: stack empty\n");
	  return 0.0;
     }
}