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.Arrays;
import java.util.Deque;
import java.util.Scanner;
import java.util.Stack;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] line = sc.nextLine().split(" ");
        Stack<Integer> stack = new Stack<Integer>();
        int a=0,b=0;
        for(int i=0; i<line.length; i++){
            if(line[i].equals("+")) {
                a = stack.pop();
                b = stack.pop();
                stack.push(b+a);
            } else if (line[i].equals("-")) {
                a = stack.pop();
                b = stack.pop();
                stack.push(b-a);
            } else if (line[i].equals("*")) {
                a = stack.pop();
                b = stack.pop();
                stack.push(b*a);
            } else {
                stack.push(Integer.parseInt(line[i]));
            }
        }
        System.out.println(stack.pop());
    }
}

