# frozen_string_literal: true
in_n, in_m = gets.chomp.split.map(&:to_i)
in_sp =
  in_n.times.to_h do
    name, price = gets.chomp.split
    [name, price.to_i]
  end
in_t = in_m.times.map { gets.chomp }

puts (in_t.sum { |t| in_sp[t] })