public static boolean isPrimeTrunc(int k, ArrayList<Integer> arr) {
		if (k / 10 == 0)
			return false;
		for (int i = 1; k / i > 0; i *= 10) {
			if (!(Collections.binarySearch(arr, k / i) >= 0)) {
				return false;
			}
		}
		for (int i = 10; k / i > 0; i *= 10) {
			if (!(Collections.binarySearch(arr, k % i) >= 0)) {
				return false;
			}
		}
		return true;
	}