Sequences of even numbers from an array in ruby

Finding the sequences of even numbers from an array in ruby

a = [1,2,3,4,444,6,5,6,7,8,44,55,333,555,66,88]
b = []
a.each_slice(2) do |l|
  if l && l[0] && l[0].even? && l[1] && l[1].even?
    b.push(l)
  end
  b
end
p b
output:  => [[444, 6], [66, 88]]