private static boolean checkSpecial(String n){
		if(Long.parseLong(n)<1e9) return false;
		int[] p = {2, 3, 5, 7, 11, 13, 17};
		String ns = n;
		for(int i=1;i<8;i++){
//			System.out.println(ns.substring(i, i+3));
			if(Integer.parseInt(ns.substring(i, i+3)) % p[i-1] != 0) return false;
		}
		return true;
	}