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);
        Deque<Integer> Stack = new ArrayDeque<>();
        String S = sc.nextLine();
        String list [] = S.split(" ");
        for(int i=0;i<list.length;i++){
            S = list[i];
            if(S.equals("+")){
                int n1 = Stack.pop();
                int n2 = Stack.pop();
                Stack.push(n1+n2);
            }
            else if(S.equals("-")){
                int n1 = Stack.pop();
                int n2 = Stack.pop();
                Stack.push(n2-n1);
            }
            else if(S.equals("*")){
                int n1 = Stack.pop();
                int n2 = Stack.pop();
                Stack.push(n1*n2);
            }
            else Stack.push(Integer.parseInt(S));
        }
        System.out.println(Stack.pop());
    }
}
