h, w = gets.split.map(&:to_i)

a = []
for i in 0..(h-1)
	b = gets.split.map(&:to_i)
	a += b
end

a = a.sort()
h.times do |y|
	(w-1).times do |x|
		print a[y * w + x].to_s + " "
	end
	puts a[y * w + w - 1]
end