Crack the code

Let's play a game I made, It's called "Crack the code". Rules: 1. The person who came up with the code using numbers, cannot give hints to the guesser. 2. If the person with the code lose, then it's the next person's turn to come up with the code. 3. The person with the code have to tell the guesser about how many characters are in the code. (Atleast 1 to 10 characters.)