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.Scanner;
import java.util.Stack;

public class Main {

	public static void main(String[] args) {
	     String[] chars = new Scanner(System.in).nextLine().split(" ");
	     Stack<String> stack = new Stack<String>();
	     for(String s: chars) {
	    	 if(s.equals("+")) {
	    		 int b = Integer.valueOf(stack.pop()), a = Integer.valueOf(stack.pop());
	    		 stack.push(Integer.toString(a+b));
	    	 }
	    	 else if(s.equals("-")) {
	    		 int b = Integer.valueOf(stack.pop()), a = Integer.valueOf(stack.pop());
	    		 stack.push(Integer.toString(a-b));
	    	 }
	    	 else if(s.equals("*")) {
	    		 int b = Integer.valueOf(stack.pop()), a = Integer.valueOf(stack.pop());
	    		 stack.push(Integer.toString(a*b));
	    	 }
	    	 else {
	    		 stack.push(s);
	    	 }
	     }
	     System.out.println(stack.pop());
	}

}

