# frozen_string_literal: true

LAW = 10**9 + 7

class Array
  def sum_of_sum
    if size >= 2
      each_cons(2)
        .map { _1.sum }
        .sum_of_sum % LAW
    else
      self[0]
    end
  end
end

def solve
  A.sum_of_sum % LAW
end

N = gets.to_i
A = gets.split.map(&:to_i)

puts solve