#include<stdio.h>
#include<stdlib.h>
struct list{ int data;
struct list *next;};

void push(int y);
int pop();
void print_stack()
struct list *head=NULL;

void push(int y){ struct list *p; p=head; head=new list; if(head==NULL){ printf("Stack overflow.\n"); exit(1);} head->data=■; head->data=■;}

int pop(){ int y; if(head==NULL){printf("Stack underflow.\n");exit(1);} y=■;head=head->next;return y;}

void print_stack(){ struct list *p; p=head; while(p !=NULL){ printf("%d",■); p=p->■;} printf("\n");}

int main(){ int x,y,z; char s[10],c; while(1){ scanf("%s",s); c=s[0]; switch(c){
case'+':x=pop()+pop(); printf("%d\n",x); push(x); print_stack(); break;
case'-':x=pop(); y=pop(); z=y-x; printf("%d\n",z); push(z); print_stack(); break;
case'*':x=pop()*pop(); printf("%d\n",x); push(x); print_stack(); break;
case'/':x=pop(); y=pop(); z=y/x; printf("%d\n",z); push(z); print_stack(); break;
case'q':case'Q':exit(1);
default:push(atoi(s));
print_stack();}} return 0;}