n, x = gets.split.map(&:to_i)
a = gets.split.map(&:to_i)
table = a.group_by(&:itself).map { |k,v| [k,v.size] }.to_h
count = 0
hx = table[x.fdiv(2)]
if hx
    if hx == 1
        count += 1
    else
        count += hx**2 - hx
    end
end
table.keys.each do |k|
    if hx && hx == k
        next
    end
    count += table[k] * (table[x - k] || 0)
end
puts count