def lscan; gets.split.map(&:to_i); end
n, m = lscan


total = 0

cnt0 = 0
cnth = 0
h = Hash.new(0)
lscan.each do |a|
  d = a%m
  if d == 0
    cnt0 += 1
  elsif d +d == m
    cnth += 1
  else
    h[d] += 1
  end
end

total += [0, cnt0-1].max
total += [0, cnth-1].max

h.keys.each do |k|
  k2 = m - k
  total += [h[k],h[k2]].min
  h[k] = 0
  h[k2] = 0
end

p n-total