n, m = gets.chomp.split(" ").map(&:to_i)
arr = n.times.map{gets.chomp.split(" ").map(&:to_i)}
hash = Hash.new { |i,j| hash[j] = [] }
arr.each do |x,y|
    hash[y] << x
end
ans = 0
hash.each do |color,box|
    hash_count = Hash.new(0)
    box.each do |i|
        hash_count[i] += 1
    end
    an = hash_count.sort_by{|a,b| b}
    many = an.pop
    ans += (box.size-many[1])
end
puts ans