n = gets.to_i
data = gets.split.map(&:to_i).sort
novelty = 0

(0..n-1).each{|i|
    if i==0
        if data[i]!=data[i+1]
            novelty = novelty + 1
        end
    elsif i==n-1
        if data[i]!=data[i-1]
            novelty = novelty + 1
        end
    else
        if data[i]!=data[i+1] && data[i]!=data[i-1]
            novelty = novelty + 1
        end
    end
}
puts novelty