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) {
		int val;
		int val2;
		int result;
		Scanner in = new Scanner(System.in);
		Stack<Integer> stack = new Stack<>();
		String expression = in.nextLine();
		String[] arr = expression.split(" ");

		for(String str : arr) {
			
			
			switch(str) {
			case "+" :
				val = stack.pop();
				val2 = stack.pop();
				stack.push(val + val2);
				break;
			case "-":
				val = stack.pop();
				val2 = stack.pop();
				stack.push(val2 - val);
				break;
			case "*":
				val = stack.pop();
				val2 = stack.pop();
				stack.push(val * val2);	
				break;
			case "/":
				val = stack.pop();
				val2 = stack.pop();
				stack.push(val2 / val);
				break;
			default:
				stack.push(Integer.parseInt(str));
				break;
			
			}
			
			
		}
		
		result = stack.pop();
		System.out.println(result);
			
	}
		
}
