1public class LuhnVerification {
2
3	static boolean checkNumber(String value) {
4		int result = 0;
5		boolean special = false;
6		for (int i = value.length() - 1; i >= 0; i--) {
7			int v = value.charAt(i) - '0';
8			if (v < 0 || v > 9)
9				return false;
10			if (special) {
11				v = v * 2;
12				if (v > 9)
13					v = v - 10 + 1;
14			}
15			result += v;
16			special = !special;
17		}
18		System.out.println(result);
19		return result % 10 == 0;
20	}
21
22	public static void main(String args[]) {
23		System.out.println(checkNumber(""));
24	}
25
26}
27