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[]) {
		Stack<Integer> stack = new Stack<Integer>();
		Scanner k = new Scanner(System.in);
		
		String[] equation = k.nextLine().split(" ");
		
		for(int x = 0; x < equation.length; x++) {
			if (equation[x].equals("+") ||equation[x].equals("-") ||equation[x].equals("*")) {
				int f = stack.pop();
				int g = stack.pop();
				if (equation[x].equals("+")) {
					stack.push(f+g);
				}
				else if (equation[x].equals("-")) {
					stack.push(g-f);
				}
				else if (equation[x].equals("*")) {
					stack.push(f*g);
				}
			}
			else {
				int y = Integer.parseInt(equation[x]);
				stack.push(y);
			}
		}
		
		System.out.println(stack.pop());
		
		
	}
}

