public class InputOutput {
    public static void main(String[] args) throws FileNotFoundException{
        PrintWriter zapis = new PrintWriter("imiona.txt");
        File file = new File("imiona.txt");
        Scanner zPliku = new Scanner(file);
        Scanner input = new Scanner(System.in);

        System.out.println("Jak się nazywasz?");
        String a = input.nextLine();
        char temp = a.charAt(0);

        if (Character.isDigit(temp)){
            System.out.println("To nie jest imie");
        }else{
            zapis.println(a);
            zapis.close();
        }

        System.out.println("Witaj "+zPliku.nextLine());
    }
}