Let \( N \) denote the number that turns up when a fair die is rolled. If the probability that the system of equations
\( x+y+z=1 \)
\( 2x+Ny+2z=2 \)
\( 3x+3y+Nz=3 \)
has unique solution is \( \dfrac{k}{6} \), then the sum of value of \( k \) and all possible values of \( N \) is:
