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.ArrayDeque;
import java.util.Deque;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		Deque<Integer> dc = new ArrayDeque<Integer>();
        
		while(scan.hasNext()) {
			String s = scan.next();
			if("+".equals(s)) {
				int x = dc.pop();
				int y = dc.pop();
				dc.push(x+y);
			}
			else if("-".equals(s)) {
				int x = dc.pop();
				int y = dc.pop();
				dc.push(y-x);
			}
			else if("*".equals(s)) {
				int x = dc.pop();
				int y = dc.pop();
				dc.push(x*y);
			}
			else {
				dc.push(Integer.valueOf(s));
			}
		}
		System.out.println(dc.pop());
		scan.close();
	}
}
