PIN is a guessing game 4 digits from 0 to 9 so that these numbers do not repeat means there is no duplicate number in two digits
When you enter a number you will see the result of guessing if you guess the four digits are all correct and in place or there is a number guessed in the wrong place or all not guessed correctly will try to guess the number 15 try as there are aids
Try it, try it and you won't lose anything