using java code answer Problem $1$: Number Pairs

Sometimes within an integer, digits come in adjacent pairs. For instance, in the number $1337$ the digit $3$ is in a pair but in the number $1373$ there are no pairs even though the digit $3$ appears twice. Write a Java method to determine the largest digit that comes in a pair within an integer. If there are no pairs return $-1.($Do not use strings in your solution $$ these are integers!$)$