import java.util.Stack;
public class PostFixCalculator {


    public Stack push;
    public static void main(String[] args) {


        String postfix = In.readLine();

        In.close();

        System.out.println(postfix);
    }

   	public static int evalPostfix(String postfix) {

		Stack valStack = new Stack();

		while (In.done()) {
			String token = In.readIdentifier();
			char c = token.charAt(0);
			if (Character.isDigit(c)) {
				valStack.push(new Integer(token));
			}
			else {
				int firstValue = ((Integer)valStack.pop()).intValue();
				int secondValue = ((Integer)valStack.pop()).intValue();
				int resultValue;

				switch (c) {
				case '+':
                                    resultValue = firstValue + secondValue;
                                    break;
				case '-':
                                    resultValue = firstValue - secondValue;
                                    break;
				case '*':
                                    resultValue = firstValue * secondValue;
                                    break;
				case '/':
                                    resultValue = firstValue / secondValue;
                                    break;

				default:
					throw new IllegalArgumentException("invalid postfix expression");
				}

				valStack.push(new Integer(resultValue));
			}
		}

		int resultValue = ((Integer)valStack.pop()).intValue();
		if (!valStack.empty()) {
			throw new IllegalArgumentException("invalid postfix expression");
		}

		return resultValue;
	}
}