n = gets.split.map(&:to_i)
ary = gets.split.map(&:to_i)
ary_new = []
ary.each_with_index do |a, index|
  if(index % 2 == 0)
    ary_new.push(a)
  end
end
ans = ary_new.delete_if { |n| n.even? }
puts ans.size