class PriorityQueue
  def initialize(array = [])
    @data = []
    array.each{|a| push(a)}
  end

  def push(element)
    @data.push(element)
    bottom_up
  end

  def pop
    if size == 0
      return nil
    elsif size == 1
      return @data.pop
    else
      min = @data[0]
      @data[0] = @data.pop
      top_down
      return min
    end
  end
  
  def poll
    if size == 0
      return nil
    else
      return @data[0]
	end
  end
  
  def size
    @data.size
  end
  
  def data
	@data
  end

  private

  def swap(i, j)
    @data[i], @data[j] = @data[j], @data[i]
  end

  def parent_idx(target_idx)
    (target_idx - (target_idx.even? ? 2 : 1)) / 2
  end

  def bottom_up
    target_idx = size - 1
    return if target_idx == 0
    parent_idx = parent_idx(target_idx)
    while (@data[parent_idx][0] < @data[target_idx][0])
      swap(parent_idx, target_idx)
      target_idx = parent_idx
      break if target_idx == 0
      parent_idx = parent_idx(target_idx)
    end
  end

  def top_down
    target_idx = 0

    # child がある場合
    while (has_child?(target_idx))

      a = left_child_idx(target_idx)
      b = right_child_idx(target_idx)

      if @data[b].nil?
        c = a
      else
        c = @data[a][0] >= @data[b][0] ? a : b
      end

      if @data[target_idx][0] < @data[c][0]
        swap(target_idx, c)
        target_idx = c
      else
        return
      end
    end
  end

  # @param Integer
  # @return Integer
  def left_child_idx(idx)
    (idx * 2) + 1
  end

  # @param Integer
  # @return Integer
  def right_child_idx(idx)
    (idx * 2) + 2
  end

  # @param Integer
  # @return Boolent
  def has_child?(idx)
    ((idx * 2) + 1) < @data.size
  end
end

N, M, X = gets.split(" ").map{|s| s.to_i}

A = Array.new(M) {PriorityQueue.new}

N.times {
	a, b = gets.split(" ").map{|s| s.to_i}
	A[b-1].push([a,b])
}

k = gets.to_i
c = gets.split(" ").map{|s| s.to_i}

cnt = []
same = PriorityQueue.new
diff = PriorityQueue.new
0.upto(M-1) {|j|
	diff.push(A[j].pop) if A[j].size > 0
}

c.max.times {
	sa, sb = same.size > 0 ? same.poll : [-Float::INFINITY, -1]
	da, db = diff.size > 0 ? diff.poll : [-Float::INFINITY, -1]
	if sa > da + X then
		same.pop
		ns = A[sb-1].pop
		same.push(ns) if ns
		cnt << sa
	else
		diff.pop
		ns = A[db-1].pop
		same.push(ns) if ns
		cnt << da + X
	end
}

total = 0
c.each {|i|
	total += cnt[0,i].sum
}
puts total