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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		ArrayList<Integer> num = new ArrayList<Integer>();
		ArrayList<String> param = new ArrayList<String>();
		int system = 0; // 文字の空白区切り　0:ON　1:OFF

		while (sc.hasNext()) {
			if (sc.hasNextInt()) {
				num.add(sc.nextInt());
			} else {
				if(system==0) param.add(sc.next());
				if(system==1) param.add(sc.nextLine());
			}
		}
		Method(num, param);
	}

	static void Method(ArrayList<Integer> num, ArrayList<String> param) {
		
		if(param.get(0).equals("+")){
			System.out.println(num.get(0) + num.get(1));
		} else {
			System.out.println(num.get(0) - num.get(1));
		}
	}
}