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);
		Stack<Integer> operand = new Stack<Integer>();
		String input = sc.nextLine();
		sc.close();
		String num = "";
		
		for(int i = 0; i < input.length(); i++) {
			String temp = input.substring(i, i + 1);
			if(temp.contentEquals("+")) {
				int j = operand.pop();
				int k = operand.pop();
				operand.push(k + j);
			}
			else if(temp.contentEquals("-")) {
				int j = operand.pop();
				int k = operand.pop();
				operand.push(k - j);
			}
			else if(temp.contentEquals("*")) {
				int j = operand.pop();
				int k = operand.pop();
				operand.push(k * j);
			}
			else if(temp.trim().length() == 0 && num.length() > 0) {
				operand.push(Integer.parseInt(num));
				num = "";
			}
			else if(temp.trim().length() > 0){
				num = num.concat(temp);
			}
		}
		System.out.println(operand.pop());
	}
}

