#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define stacksize 100
#define TYPE int
typedef struct
{
    int top;
    char items[stacksize];
} stack;
void initialize (stack *s)
{
    s->top=0;
}
void push (stack*s,char value)
{
    s->items[s->top++]=value;
}
int pop (stack*s)
{
    return s->items[--s->top];
}
int isfull(stack*s)
{
    return s->top<stacksize? 0:1;
}
int isempty(stack *s)
{
    return s->top==0? 1:0;
}
void error()
{
    printf("error");
    exit(-1);
}
typedef struct {
TYPE data;
char data2;
struct Node *next;
} Node;
Node * newNode(TYPE value,char b[]) {
Node *n=malloc(sizeof(Node));
n->data=value;
n->data2=b;
n->next=NULL;
return n;
}
typedef struct {
Node *head;
Node *tail;
} LinkedList;
void initLinkedList(LinkedList *ll){ll->head=NULL;ll->tail=NULL;}
void printLinkedList(Node *n){
printf("[");
while (n) {printf("%d ",n->data);n=(Node *)n->next;}
printf("]\n");
}
void addHead(LinkedList *ll,TYPE value,char b[]) {
Node *n=newNode(value, b);
n->next=ll->head;
ll->head=n;
if(!ll->tail) ll->tail=n; //list was empty
}
void addTail(LinkedList *ll,TYPE value,char b[]) {
Node *n=newNode(value,b);Node *tail=ll->tail;
ll->tail=n;
if (tail) tail->next=n;
else ll->head=n; // TAIL is NULL so is head!
}
TYPE deleteHead(LinkedList *ll){
Node *first=(Node*)ll->head;
if (first){
TYPE value=first->data;
ll->head=(Node *)first->next;
free(first);
if (!ll->head) ll->tail=NULL;
return value;
}
return -1 ;/* ??? this is BAD */
}
Node * search(Node *n,TYPE value,char b[]) {
if (!n) return NULL;
if (n->data==value&&n->data2==b) return n;
else return search(n->next,value,b);
}
char* topost(char a[])
{
     int i;
     char y;
     stack m;
     initialize(&m);

     char b[200];
        int j=0;

        for (i=0; i<strlen(a); i++)
        {




            if (a[i]>='0'&&a[i]<='9')
            {
                printf("%c",a[i]);
                b[j++]=a[i];
            }
            else
            {
                switch (a[i])
                {

                case'(':
                    push(&m,a[i]);
                    break;

                case '+':

                case '-':
                case '*':
                case '/':
                    push(&m,a[i]);
                    break;
                case ')':

                    while (!isempty(&m))
                    {


                       int c=pop(&m);


                        if (c=='(')

                            break;
                        else
                        {
                            printf("%c",c);
                            b[j++]=c;

                        }



                    }
                    break;


                }
            }
        }
}
int top(char a[])
{

        int i;
        int j=0;
        int c;
        char b[200];
        stack m;


        for (i=0; i<strlen(a); i++)
        {






            if (a[i]>='0'&&a[i]<='9')
            {
                printf("%c",a[i]);
                b[j++]=a[i];
            }
            else
            {
                switch (a[i])
                {

                case'(':
                    push(&m,a[i]);
                    break;

                case '+':

                case '-':
                case '*':
                case '/':
                    push(&m,a[i]);







                    break;
                case ')':

                    while (!isempty(&m))
                    {


                        c=pop(&m);


                        if (c=='(')

                            break;
                        else
                        {
                            printf("%c",c);
                            b[j++]=c;

                        }



                    }



                }
            }
        }

}
int eval(char a[])
{

        stack h;
        initialize(&h);
        char *postExp=a;
        char ch, *pt=postExp;
        while (ch=*pt++)
        {
            if (ch==' ') continue;
            if (ch<='9' && ch>='0') push(&h,ch-'0');
            else
            {
                int e,f;
                if (isempty(&h)) error();
                else e=pop(&h);
                if (isempty(&h)) error();
                else f=pop(&h);
                switch(ch)
                {
                case '+':
                    push(&h,e+f);
                    break;
                case '-':
                    push(&h,e-f);
                    break;
                case '*':
                    push(&h,e*f);
                    break;
                case '/':
                    push(&h,e/f);
                    break;
                default:
                    error();
                } // switch
            }
        }
        int z=pop(&h);
        printf("=%d",z);

return z;

}


void putinmemory(char b[])
{
    LinkedList *s;
    int v=eval(b);
    initLinkedList(s);
        Node*n=newNode(v,b);
        addTail(s,v,b);




    }




int main()
{

    stack m;
    char c;

    char p[90];
    initialize(&m);
    char a[100];
    char b[100];
     LinkedList ll;
        initLinkedList(&ll);
    while (1)
    {
        gets(a);
        topost(a);
        eval(a);


        putinmemory(a);


    }








    /*  if (a[i]==' ')
          continue;
      if(a[i]>='0'&&a[i]<='9')printf("%c",a[i]);
      if (a[i]==')'){
              if(isempty(&s)){
                  printf("error");
              }
              else{



          printf("%c",pop(&s));
              }


      }
    else{
          push(&s,a[i]);
      }

      }*/






    return 0;
}