If the set \( R = \{(a,b): a + 5b = 42,\, a,b \in \mathbb{N}\} \) has \( m \) elements and \( \displaystyle \sum_{n=1}^{m} (1 - i^{n!}) = x + i y \), where \( i = \sqrt{-1} \), then the value of \( m + x + y \) is:
\( 4 \)
\( 8 \)
\( 5 \)
\( 12 \)