Remembering Arithmetica!!!

Determine the sum of all possible positive integer values of $x$ and $y$ in the following Diophantine equation- $54x+21y=906$ Note- Note that the question asks for the sum of only the positive integer values. If there is a common value of $x$ and $y$ in two solutions then you have to add them separately. For example- Say 1 set of solution is $a,b$ and the other is $b,c$ then their sum is $2b+a+c$ . This applies for a common value of $x,y$ in a single set of solution.