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

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

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

A.each {|a|
	a.sort_by!{|x| -x}
}

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

cnt = []
cpos = Array.new(M, 0)
same = []
diff = []
0.upto(M-1) {|j|
	diff << [A[j][0], j] if A[j].length > 0
}
diff.sort!.reverse!
c.max.times {
	sa, sb = same.length > 0 ? same[0] : [-Float::INFINITY, -1]
	da, db = diff.length > 0 ? diff[0] : [-Float::INFINITY, -1]
	
	if sa > da + X then
		same.shift
		cpos[sb] += 1
		if cpos[sb] < A[sb].length then
			same << [A[sb][cpos[sb]], sb]
			same.sort!.reverse!
		end
		cnt << sa
	else
		diff.shift
		cpos[db] += 1
		if cpos[db] < A[db].length 
			same << [A[db][cpos[db]], db]
			same.sort!.reverse!
		end
		cnt << da + X
	end
}

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