Return a random value

Question

Build a piece of code in c# language : (method/function) Which returns a random value between 1 & 6 except those numbers which are passed at the time of calling.

Just as . . .

//Definition

Private int rdm (int [] ) {

return int }

//calling

rdm(new int {3,5} )

//output 4 Or 2 Or 6 Or 1