N, M = gets.split.map(&:to_i)
A = gets.split.map(&:to_i)

count = Hash.new(0)
A.each do |x|
  count[x % M] += 1
end

ans = 0
added = Set.new
count.each_key do |x|
    y = -x % M
    next if added.include?(x) or added.include?(y)
    added << x << y
    if x == y
        ans += 1
    else
        ans += [count[x], count[y]].max
    end
end

puts ans