class Main {
	public static void main (String[] args) {
		String x = "1234";
		System.out.println(x.charAt(0) >= '0' && x.charAt(0) <= '9');
		x = "a123";
		System.out.println(x.charAt(0) >= '0' && x.charAt(0) <= '9');
	}
}

//https://pt.stackoverflow.com/q/111739/101