Let \( \alpha \) be a solution of \( x^2 + x + 1 = 0 \), and for some \( a \) and \( b \) in \( \mathbb{R} \), If \( \dfrac{4}{\alpha^4} + \dfrac{m}{\alpha^a} + \dfrac{n}{\alpha^b} = 3 \), then \( m + n \) is equal to ______.
\( 8 \)
\( 7 \)
\( 11 \)
\( 3 \)