using System;

using System.Collections.Generic;

public class Program

{

    public class Expression{

        public string Left {get; set;}

        public string Right {get; set;}

        public string Operator {get; set;}

        public Expression (string left, string right, string op){

            Left = left;

            Right = right;

            Operator = op;

        }

    }

    public class PostFixCalculator{

        public int Result {get; set;}

        public Expression Expression{get; set;}

        public PostFixCalculator(Expression exp){

             Expression = exp;

        }

        public int Calculate(){

            int result = 0;

            int left;

            int right;

            int.TryParse(Expression.Left, out left);

            int.TryParse(Expression.Right, out right);

            switch(Expression.Operator){

                case "+":

                result = left + right;

                break;

                case "-":

                result = left - right;

                break;

                case "*":

                result = left * right;

                break;

                case "/" :

                result = left / right;

                break;

                default:

                break;

            }

            return result;

        }

    }

    public class Parser{

        public string Input {get; set;}

        public Expression Exp {get; set;}

        public Parser(){}

        public Expression ParseSimpleInput(string input){

            var tokens = input.Split(' ');

            return new Expression( tokens[0], tokens[1], tokens[2]);

        }

    }

    public static void Main()

    {

        var input = Console.ReadLine();

        var parser = new Parser();

        var exp = parser.ParseSimpleInput(input);

        var result = new PostFixCalculator(exp).Calculate();

        Console.WriteLine(result);

    }

}