Fill with { same , same } and { white , black } and { black , white }
ans = ( ( ( ans + Ways ( col + 1 , comp + 1 , 0 , 0 ) ) + Ways ( col + 1 , comp + 1 , 1 , 0 ) ) + Ways ( col + 1 , comp + 1 , 0 , 1 ) ) ;