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);
        String[] line = sc.nextLine().split(" ");
        ArrayDeque<Integer> stack = new ArrayDeque<>();
        for (String x : line) {
            char c = x.charAt(0);
            if (c == '+' || c == '-' || c == '*') {
                int second = stack.pop();
                int first = stack.pop();
                if (c == '+') {
                    first += second;
                } else if (c == '-') {
                    first -= second;
                } else {
                    first *= second;
                }
                stack.push(first);
            } else {
                stack.push(Integer.parseInt(x));
            }
        }
       System.out.println(stack.pop());
    }
}
