Собственно проблема в том, что Валидатор не согласен и видит бесконечный цикл.
package com.javarush.task.task19.task1908;
import java.io.*;
import java.util.Scanner;
/*
Выделяем числа
*/
public class Solution {
public static void main(String[] args) throws IOException{
BufferedReader bfreader = new BufferedReader(new InputStreamReader(System.in));
FileReader reader = new FileReader(bfreader.readLine());
BufferedReader bfreader2 = new BufferedReader(new InputStreamReader(System.in));
FileWriter write = new FileWriter(bfreader2.readLine());
Scanner sc = new Scanner(reader);
String answer = "";
while (sc.hasNext()){
String [] str = sc.nextLine().split(" ");
for(int i = 0; i < str.length; i++){
try { answer = answer + Integer.parseInt(str[i]) + " ";
} catch (Exception ignored) {
}
// for ends
}
}
write.write(answer.trim());
write.close();
sc.close();
reader.close();
bfreader.close();
bfreader2.close();
}
}