novelty = Array.new(1000000001, 0) n = gets.to_i data = gets.split.map(&:to_i) n.times{|i| novelty[data[i]] = novelty[data[i]] + 1 } ans = 0 (1..1000000000).each{|i| if novelty[i]==1 ans = ans + 1 end } puts ans