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

#define MAX_RAZMER 10

typedef struct {
    double chisla[MAX_RAZMER];
    int vershina;
} StEk;

void inicStEk(StEk* stek) {
    stek->vershina = 0;
}

int isEmpty(StEk* stek) {
    return stek->vershina == 0;
}

int isFull(StEk* stek) {
    return stek->vershina == MAX_RAZMER;
}

void push(StEk* stek, double chislo) {
    if (isFull(stek)) {
        printf("not enough operands\n");
        exit(1);
    }
    stek->chisla[stek->vershina] = chislo;
    stek->vershina++;
}

double pop(StEk* stek) {
    if (isEmpty(stek)) {
        printf("not enough operands\n");
        exit(1);
    }
    return stek->chisla[--stek->vershina];
}

int main() {
    StEk stek;
    inicStEk(&stek);
    char bufer[256];
    while (fgets(bufer, sizeof(bufer), stdin) != NULL) {
        if (bufer[0] == '\n') {
            if (isEmpty(&stek)) {
                printf("no input\n");
            } else {
                double result = pop(&stek);
                printf("%.2lf\n", result);
            }
            return 0;
        }

        char* konec;
        double chislo = strtod(bufer, &konec);
        char c = konec[0];

        if (c == '\n' && *bufer != '\n' && *bufer != ' ') {
            push(&stek, chislo);
        } else if (c == '+' || c == '-' || c == '*' || c == '/') {
            if (isEmpty(&stek)) {
                printf("not enough operands\n");
                return 0;
            }
            double b = pop(&stek);
            if (isEmpty(&stek)) {
                printf("not enough operands\n");
                return 0;
            }
            double a = pop(&stek);
            if (c == '+') {
                push(&stek, a + b);
            } else if (c == '-') {
                push(&stek, a - b);
            } else if (c == '*') {
                push(&stek, a * b);
            } else if (c == '/') {
                if (b == 0) {
                    printf("division by zero\n");
                    return 0;
                }
                push(&stek, a / b);
            }
        } else if (!isdigit(c) || !isalpha(c)) {
            printf("bad input\n");
            return 0;
        } else {
            printf("no input\n");
            return 0;
        }
        for (int i = 0; i < stek.vershina; i++) {
            printf("%.2lf ", stek.chisla[i]);
        }
        printf("\n");
    }
    printf("no input\n");
    return 0;
}