#include "stdio.h"
typedef struct
{
    int datas[100];
    top;
}NUMSTACK;
typedef struct
{
    char datas[100];
    top;
}OPSTACK;
int jfirst(char oper1,char oper2,char s);
float caculate(float num1,float num2,char oper);
main()
{
    OPSTACK op;
    NUMSTACK num;
    //初始化
    op.datas[0]=';';
    op.top=1;
    num.top=0;
    //输入
    s=gets();
    for (int i=0;i<strlen(s);i++)//字符的扫描
    {  if s[i] //如果是数字
        num.datas[num.top]=s[i];
        num.top++;
        //如果是字符
          if (jfirst(op.datas[op.top-1],s[i]))
              //压栈
              {
              op.datas[op.top]=s[i];
              op.top++;
              }
           else
           {
                 while  !(jfirst(op.datas[op.top-1],s[i]))
                 {
                     //弹出操作数
                     num2=num.datas[num.top-1];
                     num.top--;
                     num1=num.datas[num.top-1]
                     num.top--;
                     oper=op.datas[op.top-1];
                     op.top--;
                     result=caculate(num1,num2,oper);
                     //压栈
                     num.datas[num.top]=result;
                     num.top++;                              
                     
                     }
               }
              
        }
       
}
float caculate(float num1,float num2,char oper)
{
    switch(oper)
    {
        case '-': return num1-num2;break;
        case '+': return num1+num2;break;
        case '*': return num1*num2;break;
        case '/': return num1/num2;break;
        default: return 0;
    }
}
int jfirst(char oper1,char oper2)
{
   if (oper1=='*' || oper1=='/' || oper2==';')
       return 0;
   else
   {
       if (oper2=='-' || oper2=='+')
         return 0;

        else
          return 1;
    }
}