N = gets.to_i
B = gets.split.map(&:to_i)
S = Array.new(N + 1, 0)
B.each_with_index do |b,i|
  S[i + 1] = S[i] + b
end

t = 0
(1 .. N).inject(0) do |m, n|
  m_ = S[m] >= n ? m : (m .. N).find{|m_| S[m_] >= n }
  t += (n - m_).abs
end

puts t