#include <stdio.h>
#define SIZE 10
double stack[SIZE];
int sp;

void push(double value);
double pop(void);
int isFull(void);
int isEmpty(void);
void answer(void);
void reset(void);

int main(void)
{
    reset();

    int resp;
    double data, a, b;

    while(1){
        
        scanf("%d", &resp);

        if(resp == 9) break;

        switch(resp){
            case 1:
                b = pop();
                a = pop();
                push(a + b);
                break;

            case 2:
                b = pop();
                a = pop();
                push(a - b);
                break;

            case 3:
                b = pop();
                a = pop();
                push(a * b);
                break;

            case 4:
                b = pop();
                a = pop();
                push(a / b);
                break;

            case 5:
                scanf("lf", &data);
                printf("data%f\n", data);
                push(data);
                break;
        }
    }

    answer();
    return 0;
}

void push(double value)
{
    if(isFull()){
        printf("スタックは満杯です\n");
    }else{
        stack[sp++] = value;
    }
}

double pop(void)
{
    double value;

    if(isEmpty()){
        printf("スタックは空です\n");
        return 0;
    }else{
        value = stack[--sp];
        return value;
    }
}

int isFull(void)
{
    if(sp == SIZE){
        return 1;
    }else{
        return 0;
    }
}

int isEmpty(void)
{
    if(sp == 0){
        return 1;
    }else{
        return 0;
    }
}

void answer(void)
{
    if(isEmpty()){
        printf("計算結果がありません\n");
    }else{
        printf("\nanswer:%f\n", stack[sp-1]);
    }
}
void reset(void)
{
    sp = 0;
}