Problem:
Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

The input is given from Standard Input in the following format:

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

namespace A
{
    class Program
    {


        static void Main(string[] args)
        {

            //Console.WriteLine("Please input + or -");
            var input = Console.ReadLine();
            string[] arr = input.Split(' ');
            //Console.WriteLine("{0}{1}{2}",arr[0], arr[1], arr[2]);

            string op = "";

            while (arr[1] != "+" && arr[1] !="-") {
                Console.WriteLine("Pleas input + or -");
                op = Console.ReadLine();
                arr[1] = op;

                Console.Write(op);
            }

            var a = int.Parse(arr[0]);
            var b = int.Parse(arr[2]);
            int s;

            if (op == "+")
            {
                s = a + b;
            }
            else
            {
                s = a - b;
            }
            Console.Write(s);
        }

            
    }
 }