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) {
		Scanner s = new Scanner(System.in);
		Stack<Long> stack = new Stack<>();
		while (s.hasNext()) {
			String in = s.next();
			try {
				stack.push(Long.parseLong(in));
			} catch (Exception e) {
				switch (in) {
					case "+":
						stack.push(stack.pop() + stack.pop());
						break;
					case "-":
						long x1 = stack.pop();
						long x2 = stack.pop();
						stack.push(x2 - x1);
						break;
					case "/":
						long x11 = stack.pop();
						long x22 = stack.pop();
						stack.push(x22 / x11);
						break;
					case "*":
						stack.push(stack.pop() * stack.pop());
						break;
				}
			}
		}
		System.out.println(stack.pop());
	}
}

