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 Scala (2.11.7) (judge verdict: Accepted)

object Main extends App {
  val lines = scala.io.Source.stdin.getLines().toList

  // Q2
  import scala.util.Try
  lines.foreach { line =>
    val result = line.split("\\s+") match {
      case Array(a, "+", b) => Try(a.toInt + b.toInt).toOption
      case Array(a, "-", b) => Try(a.toInt - b.toInt).toOption
      case _ => None
    }
    result.foreach(println)
  }
}