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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
// using System.Linq;

namespace easy_Atcoder
{
    class Program
    {
        static void Main(string[] args)
        {
            // float[] ABN = Array.ConvertAll(Console.ReadLine().Split(),float.Parse);
            // int[] nx = Array.ConvertAll(Console.ReadLine().Split(),int.Parse);
            // long K = long.Parse(Console.ReadLine());
            // int[] abc = Array.ConvertAll(Console.ReadLine().Split(),int.Parse);
            // string S = Console.ReadLine();
            // int a = int.Parse(Console.ReadLine());
            // int b = int.Parse(Console.ReadLine());
            // int h = int.Parse(Console.ReadLine());
            // float N = float.Parse(Console.ReadLine());
            // string c = Console.ReadLine();
            // string B = Console.ReadLine();
            string[] AopB = Console.ReadLine().Split();
            // var s = (new string[] { Console.ReadLine(), Console.ReadLine(), Console.ReadLine() }).Select(float.Parse);
            // float[] a = Array.ConvertAll(Console.ReadLine().Split(),float.Parse);
            // var X = Console.ReadLine();
            // int[,] abcd = new int[NMQ[2],4];
            // int[] A = new int[NMQ[0]];
            // int[] A_num = new int[NMQ[0]];
            // for(int i = 0; i<A_num.Length;i++){
            //     A_num[i] = 0;
            // }
            int A = int.Parse(AopB[0]);
            int B = int.Parse(AopB[2]);
            Console.WriteLine(AopB[1]=="+"?A+B:A-B);
        }
        //最小公倍数
        static long Lcm(long a, long b)
        {
            return a/Gcd(a,b)*b;
        }

        //最大公約数
        static long Gcd(long m, long n)
        {
            if(n==0)return m;
            return Gcd(n,m%n);
        }
    }
}