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

#define LINESIZE 100

struct kalkulacka{
    float cislo; };

int main() {
    struct kalkulacka number[LINESIZE];
    memset(number, 0, sizeof(struct kalkulacka) * LINESIZE);
    char line[LINESIZE];
    size_t velkost;
    memset(line, 0, LINESIZE);
    int a = 0;
    int i;
    int input = 0;
    float p;
    float vys;
    while (fgets(line, LINESIZE, stdin)) {
        velkost = strlen(line);
        if (velkost == 1 && line[velkost - 1] == '\n') {

            break;
        }
        if (input >= 10){

            break;
        }
        if (line[0] == '+' || line[0] == '-' || line[0] == '*' || line[0] == '/') {
            input =+ 2;
            if (line[0] == '+') {
                number[a - 2].cislo = number[a - 2].cislo + number[a - 1].cislo;
                a--;
            }
            if (line[0] == '-') {
                number[a - 2].cislo = number[a - 2].cislo - number[a - 1].cislo;
                a--;
            }
            if (line[0] == '*') {
                number[a - 2].cislo = number[a - 2].cislo * number[a - 1].cislo;
                a--;
            }
            if (line[0] == '/') {
                if (number[a - 1].cislo == 0){
                    printf("division by zero");
                    vys = 1;
                    a = 0;
                }
                else {
                    number[a - 2].cislo = number[a - 2].cislo / number[a - 1].cislo;
                    a--;
                }
                }
        }
        else {
            if(line[0] >= 'a' && line[0] <= 'z') {
                printf("bad input\n");
                vys = 1;
                break;
            }
            else {
                p = atof(line);
                number[a].cislo = p;
                a++;
                input++;
            }
        }

        for (i = 0; i < a; i++){
            printf("%.2f ", number[i].cislo);
        }

            printf("\n");

    }
    if (vys != 1) {
        printf("no input\n");
    }
    return 0;
}