Notes

Template in C

Constraints

2 ≤ the number of operands in the expression ≤ 100
1 ≤ the number of operators in the expression ≤ 99
-1 × 109 ≤ values in the stack ≤ 109

Input

An expression is given in a line. Two consequtive symbols (operand or operator) are separated by a space character.

You can assume that +, - and * are given as the operator and an operand is a positive integer less than 106

Output

Print the computational result in a line.

Examples

Input

1 2 +


Output

3


Input

1 2 + 3 4 - *


Output

-3
import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
			while(sc.hasNext()){
				String str = sc.nextLine();
				String[] s = str.split(" ");
				Stack<Integer> stk = new Stack<Integer>();
				if(s.length > 2){
					for(int i=0;i<s.length;i++){
						if(s[i].toString().equals("*"))
							stk.push((stk.pop()*stk.pop()));
						else if(s[i].toString().equals("/")){
							int a=stk.pop(),b=stk.pop();
							stk.push(b/a);
						}
						else if(s[i].toString().equals("+"))
							stk.push((stk.pop()+stk.pop()));
						else if(s[i].toString().equals("-")){
							int a=stk.pop(),b=stk.pop();
							stk.push(b-a);
						}
						else{
							stk.push(Integer.valueOf(s[i].toString()));
						}
					}
					System.out.printf("%d\r\n",stk.pop());
				}
			}
	}
}
