How to compare same cell and another for differences

basically I want to check rows in excel (automatically), scan a full database and return the rows where the values in one column are the same and in another aren’t the same.

Example:

A B C
-----
1 7 2
2 8 4
1 8 3
1 7 4
2 6 3

Would check and return a table like this(check A for similarities and B for differences)

A
1
2