#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();

    while(1){
        int menu;
        double data;
        double a,b;

        scanf("%d",&menu);

        switch(menu){
        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:     // データ入力
            scanf("%lf",&data);
            push(data);
            printf("data:%lf\n",data);
            break;

        case 9:     // 終了
            answer();
            return 0;
        }
    }

    answer();

    return 0;
}

void push(double value)
{
    if(!isFull())
        stack[sp++] = value;
}

double pop(void)
{
    if(!isEmpty())
        return stack[--sp];

    return 0;
}

int isFull(void)
{
    return sp >= SIZE;
}

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

void answer(void)
{
    printf("\nanswer:%lf\n", pop());
}

void reset(void)
{
    sp = 0;
}