#include<stdio.h>
#include<assert.h>
#include<string.h>
#include<stdlib.h>
#include<ctype.h>
#define STACK_SIZE 10

struct stack
{
   float values[STACK_SIZE];
   int size;
};

void push_stack(struct stack* mystack, float value)
{
    assert(mystack->size<STACK_SIZE);
    mystack->values[mystack->size]=value;
    mystack->size+=1;
}

int switch_operators(const char input[])
{

    switch (input[0])
    {
    case '+':
        return 0;
        break;
    case '-':
        return 0;
        break;
    case '*':
        return 0;
        break;
    case '/':
        return -1;
        break;
    }   
	
}

float pop_stack(struct stack* mystack,const char input[])
{
    assert(mystack->size>1);
    float val1=mystack->values[mystack->size-2];
    float val2=mystack->values[mystack->size-1];
    switch (input[0])
    {
    case '+':
        mystack->size-=2;
        return val1+val2;
        break;
    case '-':
        mystack->size-=2;
        return val1-val2;
        break;
    case '*':
        mystack->size-=2;
        return val1*val2;
        break;
    case '/':
        mystack->size-=2;
        return val1/val2;
        break;
    default:
        break;
    }
}

void print_stack(struct stack* mystack)
{
    for(int i=0;i<mystack->size;i++)
    {
        printf("%.2f",mystack->values[i]);
        if (i<mystack->size-1)
        {
            printf(" ");
        }
    }
    printf(" \n");
}


int main()
{
        struct stack mystack;
        memset(&mystack,0,sizeof(struct stack));
        char input[1000];
        while (fgets(input,sizeof(input),stdin)!=NULL)
        {	
            int flag=switch_operators(input);
  		if(mystack.size==10)
        	{
                	printf("full stack\n");
               		 return 0;
       		}	

	   	if((input[0]>=0 && input[0]<=47 && input[0]!=43 && input[0]!=45 && input[0]!=42 && input[0]!=47 && (input[0]<48 || input[0]>57)) || (input[0]>=58 && input[0]<=127))
		{
    			printf("bad input\n");
    			return 0;
		}
            input[strcspn(input,"\n")]=0;
            if (flag==0 || flag==-1)
            {
			if(flag==-1 && mystack.values[mystack.size-1]==0)
			{
				printf("division by zero\n");
				return 0;
			}
			if(mystack.size==1)
			{
				printf("not enough operands\n");
				return 0;
			}
                float op_num=pop_stack(&mystack,input);
                push_stack(&mystack,op_num);
            }
            else
            {
                char* ptr;
                float num=strtof(input,&ptr);
                push_stack(&mystack,num);
            }
            print_stack(&mystack);
        }
		printf("no input\n");
        return 0;
}