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) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int sum = 0;
		String[] array = scan.nextLine().split(" ");
		Stack<String> stack = new Stack<>();
		
		for(int i = 0; i < array.length; i++) {
			try {
				stack.push(String.valueOf(Integer.parseInt(array[i])));
			
			
			}catch(NumberFormatException e){
				int x = Integer.parseInt(stack.pop());
				int y = Integer.parseInt(stack.pop());
		           
				if(array[i].equals("+")) {
					stack.push(String.valueOf(y+x));
				} else if(array[i].equals("-")) {
					stack.push(String.valueOf(y-x));
					} else if(array[i].equals("*")) {
						stack.push(String.valueOf(y*x));
					} else if(array[i].equals("/")) {
						stack.push(String.valueOf(y/x));
					}
		    }    
			//System.out.println(stack);
		}
		System.out.println(stack.pop());
	}
}
