try{
        FileOutputStream zapis = new FileOutputStream("Vysledek.txt");
        FileInputStream nacteni = new FileInputStream("Zadani.txt");
        Scanner scan = new Scanner(nacteni);
        Scanner sc = new Scanner(System.in);
     //   System.out.println("Zadejte pocet radek matice:");
        int radky = Integer.parseInt(scan.next());
        if (radky <= 0) {
            while (radky <= 0) {
                System.out.println("Musi byt zadane kladne cislo:");
                radky = sc.nextInt();
            }
        }
        System.out.println("Zadejte pocet sloupcu matice:");
        int sloupce = Integer.parseInt(scan.next());
        if (sloupce <= 0) {
            while (sloupce <= 0) {
                System.out.println("Musi byt zadane kladne cislo:");
                sloupce = sc.nextInt();
            }
        }