import java.util.Scanner;

class Stack<Item> {
	private Node first; // 栈顶元素
	private int N; // 元素数量
	private class Node {
		Item item;
		Node next;
	}
	
	public boolean isEmpty() {
		return first == null;
	}
	
	public int size() {
		return N;
	}
	
	public void push(Item item) {
		Node oldfirst = first;
		first = new Node();
		first.item = item;
		first.next = oldfirst;
		N++;
	}
	
	public Item pop() {
		Item item = first.item;
		first = first.next;
		N--;
		return item;
	}
}

public class Evaluate {
	@SuppressWarnings("resource")
	public static void main(String[] args) {
		Stack<String> ops = new Stack<String>();
		Stack<Double> vals = new Stack<Double>();
		Scanner scanner = new Scanner(System.in);
		
		while(scanner.hasNext()) {
			String s = scanner.next();
			if (s.equals("("))
			{
				
			} else if (s.equals("+")) {
				ops.push(s);
			} else if (s.equals("-")) {
				ops.push(s);
			} else if (s.equals("*")) {
				ops.push(s);
			} else if (s.equals("/")) {
				ops.push(s);
			} else if (s.equals("sqrt")) {
				ops.push(s);
			} else if (s.equals(")")) {
				String op = ops.pop();
				Double v = vals.pop();
				if (op.equals("+")) {
					v = vals.pop() + v;
				} else if (op.equals("-")) {
					v = vals.pop() - v;
				} else if (op.equals("*")) {
					v = vals.pop() * v;
				} else if (op.equals("/")) {
					v = vals.pop() / v;
				} else if (op.equals("sqrt")) {
					v = Math.sqrt(v);
				}
				vals.push(v);
			} else {
				vals.push(Double.parseDouble(s));
			}
		}
		System.out.println(vals.pop());
	}
}