Problem:
Simple Calculator

Write a program which reads two integers a, b and an operator op, and then prints the value of a op b.

The operator op is '+', '-', '*' or '/' (sum, difference, product or quotient). The division should truncate any fractional part.

Input

The input consists of multiple datasets. Each dataset is given in the following format.

a op b

The input ends with a dataset where op = '?'. Your program should not process for this dataset.

Output

For each dataset, print the value in a line.

Constraints

0 ≤ a, b ≤ 20000

No divisions by zero are given.

Sample Input 1

1 + 2
56 - 18
13 * 2
100 / 10
27 + 81
0 ? 0

Sample Output 1

3
38
26
10
108

Solution in C# (judge verdict: Accepted)

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

namespace AtCoder
{
	class Program
	{
		static void Main(string[] args)
		{
			var Instance = new Question();
			Instance.Exec();
		}
	}

	public class Question
	{
		public void Exec()
		{
			List<long> answerList = new List<long>();
			string[] array = { "", "", "" };

			while (array[1] != "?") {
				array = Console.ReadLine().Split(' ');
				long a = long.Parse(array[0]);
				string op = array[1];
				long b = long.Parse(array[2]);
				long answer = 0;

				if (array[1] == "?") {
					break;
				}

				switch (op) {
					case "+":
					default:
						answer = a + b;
						break;
					case "-":
						answer = a - b;
						break;
					case "*":
						answer = a * b;
						break;
					case "/":
						answer = a / b;
						break;
				}

				answerList.Add(answer);
			}

			foreach (var item in answerList) {
				Console.WriteLine($"{item}");
			}

			Console.ReadKey();
		}
	}
}