Alex, Bert, and Carl know a secret two digit number. It is known that one of them is a knight who always tells the truth, one is a liar who makes all false statements, and one is a knave who alternates between true and false statements. Each one of them makes statements about the number as follows:

Alex:

1: One digit is 1.

2: The sum of the digits is 8.

3: Bert's second statement is false.

Bert:

1: One digit is 3.

2: The difference of the digits is 4.

3: Exactly one of Carl's statements is true.

Carl:

1: One digit is 6.

2: Alex's first statement is false.

3: The first digit is larger.

What is the secret number?