Here is my solution. It works fine in eclipse, but it crashes in here.
Could you tell me what is wrong?

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Sum {

    public static void main(String[] args) {

    int x,y;
    long z;

    try {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        x = Integer.parseInt(bf.readLine());
        y = Integer.parseInt(bf.readLine());
        bf.close();
        z = x+y;
        System.out.println(z);
    } catch (IOException e) {
        System.out.println(e);
    }

    }
}

Test: 1 2 (in one line)
Verdict: Crash

Besides BufferedReader use java.util.StringTokenizer (better) or java.io.StreamTokenizer.