import java.io.InputStream;

import java.util.Scanner;

public final class MyScanner {

private final Scanner scanner;

public String next() { return scanner.next(); }

public int nextInt() { return (int) nextDouble(); }

public double nextDouble() {

return readValue(scanner.next());

}

private double readValue(final String value) {

double newValue;

try {

newValue = Double.parseDouble(value);

} catch(NumberFormatException e) {

newValue = -1;

}

return newValue;

}

public void close() {

scanner.close();

}

public static void errorMessage() { System.out.println("Недопустимый ввод, попробуйте ещё раз"); }

public MyScanner(InputStream in) {

this.scanner = new Scanner(in);

}

}