using System.Text.RegularExpressions;
using System;
class stack
{
	private string[] buffer;
	private int top;
	private int maxsize;
	public stack(int size)	
	{// ??????
		top=0;
		maxsize=size;
		buffer=new string[maxsize];
	}//????? ?????? 

	private bool isEmpty()
	{//???? ???? ????
		if(top<=0) return true;
		return false;
	}//end of isEmpty

	private bool isFull()
	{
		if(top>=maxsize) return true;
		return false;
	}//end of isFull

	public string pop()
	{
		if(!isEmpty()) return buffer[--top];
		return null;
	}//end of pop

	public void push(string elm)
	{
		if(!isFull())buffer[top++]=elm;
	}//end of push

	public string topElm()
	{
		if(!isEmpty()) return buffer[top-1];
		return null;
	}
}// end of class stack
class infixToPostfix
{
	string [] exp;
	string operators;
	int expLen,tokenIndex;
	stack st;
	public infixToPostfix(string [] expEval,int len)
	{
		exp=expEval;
		expLen=len;
		tokenIndex=0;
		operators="^*/+-";
		st=new stack(len);
	}//end of infixToPostfix

	private string getToken()
	{
		string temp;
		if(this.tokenIndex>=expLen) return null;
		temp=exp[this.tokenIndex++];
		return temp;
	}//end of get Token

	private bool isOperator(string op)
	{
		if(op.Length==0) return false;
		else if((op.Length>1)||char.IsDigit(op,op.Length-1)||(operators.IndexOf(op)==-1)) return false;
		return true;
	}//end of isOperator

	public int getOpLen()
	{
		return expLen;
	}//end of getOpLen

	public string [] inToPost()
	{
		string temp1;
		string temp2;
		string [] operands=new string[expLen];
		int operandIndex=0;
		while((temp1=getToken())!=null)
		{
			if(temp1.Equals("("))
				st.push(temp1);
			else if(temp1.Equals(")"))
			{
				while(st.topElm()!=null && !st.topElm().Equals("("))
				{
					temp2=st.pop();
					operands[operandIndex++]=temp2;
				}
				st.pop();
			}
			else if(isOperator(temp1))
			{
				if((temp2=st.topElm())!=null)
				{
					if(temp2.Equals("(")) st.push(temp1);
					else if(operators.IndexOf(temp1)<operators.IndexOf(temp2))st.push(temp1);
					else
					{
						operands[operandIndex++]=st.pop();
						st.push(temp1);
					}
				}
				else st.push(temp1);
			}
			else operands[operandIndex++]=temp1;
		}
		while((temp1=st.pop())!=null)operands[operandIndex++]=temp1;
		expLen=operandIndex;
		return operands;
	}
}// end of infixToPostfix class

class eval{
	stack st;
	string[] exp;
	int expLen;
	string[] errorMsg={" ","Invalid number of operands.","divid by ziro.","Invalid Operators."};

	public eval(string[] postfix,int len)
	{
		st=new stack(len);
		exp=postfix;
		expLen=len;
	}//end of eval

	private void assert(int msgNumber){
		Console.WriteLine("Error({0}):"+errorMsg[msgNumber],msgNumber);
		Environment.Exit(1);
	}//end of assert

	public double compute(){
		string op1,op2;
		int i;
		for(i=0;i<expLen;i++){
			if(exp[i].Length==0) continue;
			if(char.IsDigit(exp[i],exp[i].Length-1)) st.push(exp[i]);
			else{
				switch(exp[i]){
					case "^":
						op2=st.pop();
						op1=st.pop();
						if(op1==null||op2==null) assert(1);
						st.push(Math.Pow(Convert.ToDouble(op1),Convert.ToDouble(op2)).ToString());
						break;
					case "*":
						op2=st.pop();
						op1=st.pop();
						if(op1==null||op2==null) assert(1);
						st.push((Convert.ToDouble(op1)*Convert.ToDouble(op2)).ToString());
						break;
					case "/":
						op2=st.pop();
						op1=st.pop();
						if(op1==null||op2==null) assert(1);
						if(op2.Equals("0")) assert(2);
						st.push((Convert.ToDouble(op1)/Convert.ToDouble(op2)).ToString());
						break;
					case "+":
						op2=st.pop();
						op1=st.pop();
						if(op1==null||op2==null) assert(1);
						st.push((Convert.ToDouble(op1)+Convert.ToDouble(op2)).ToString());
						break;
					case "-":
						op2=st.pop();
						op1=st.pop();
						if(op1==null||op2==null) assert(1);
						st.push((Convert.ToDouble(op1)-Convert.ToDouble(op2)).ToString());
						break;
					default:
						assert(3);
						break;
				}//end of swich
			}// end of else
		}//end of for
		return Convert.ToDouble(st.pop());
	}//end of compute 
}// end of eval class 

class test
{
	public static void Main(string[] args)
	{

		string t;
		string [] temp;
		getspace gs=new getspace();
		Console.WriteLine("please enter your Expression:");
		t=Console.ReadLine();
		t=gs.gets(t);
		temp=t.Split(' ');
		infixToPostfix in2pos=new infixToPostfix(temp,temp.Length);
		temp=in2pos.inToPost();
		int len=in2pos.getOpLen();
		eval ev =new eval(temp,len);
		Console.WriteLine(ev.compute().ToString());
	}
}
class getspace{
	public string gets(string s1)
	{
		string s2=null,op="1234567890";
		int i=0,j=0;
		while(st[i]!=null)
			if(st[i].CompareTo(op)!=-1)
			{
				s2[1]=s1[i++];
				s2[1]=' ';
			};
		return s2;
	}
}