using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
        // Test();
    }
    static void Test()
    {
        var r = new Random();
        var count = 0;
        while (true)
        {
            var n = 4;
            var m = n;
            var x = r.Next(10);
            var map = new int[n][];
            for (var i = 0; i < n; ++i) map[i] = new int[] { r.Next(10), r.Next(m) + 1 };
            var k = 1;
            var c = new int[k];
            for (var i = 0; i < k; ++i) c[i] = r.Next(n + 1);
            // 愚直解
            var s1 = All(n, m, x, map, k, c);
            // 作成解
            var s2 = Contest(n, m, x, map, k, c);
            if (s1 != s2)
            {
                WriteLine($"{n} {m} {x} {k}");
                WriteLine(string.Join("\n", map.Select(m => string.Join(" ", m))));
                WriteLine(string.Join(" ", c));
                WriteLine(s1);
                WriteLine(s2);
                return;
            }
            ++count;
            if (count % 1000 == 0) WriteLine(count);
        }
    }
    static long All(int n, int m, int x, int[][] map, int k, int[] c)
    {
        var ans = 0L;
        Permutate(n, list =>
        {
            var pts = 0L;
            foreach (var ci in c)
            {
                var gset = new HashSet<int>();
                for (var i = 0; i < ci; ++i)
                {
                    pts += map[list[i]][0];
                    gset.Add(map[list[i]][1]);
                }
                pts += gset.Count * (long)x;
            }
            ans = Math.Max(ans, pts);
        });
        return ans;
    }
    static void Permutate(int n, Action<int[]> action)
    {
        var seed = new int[n];
        for (var i = 0; i < n; ++i) seed[i] = i;
        var used = new bool[n];
        var perm = new int[n];
        Permutate(0, seed, perm, used, action);
    }
    static void Permutate(int pos, int[] seed, int[] perm, bool[] used, Action<int[]> action)
    {
        if (pos == used.Length) action(perm);
        for (var i = 0; i < used.Length; ++i)
        {
            if (used[i]) continue;
            perm[pos] = seed[i];
            used[i] = true;
            Permutate(pos + 1, seed, perm, used, action);
            used[i] = false;
        }
    }
    static void Solve()
    {
        var c = NList;
        var (n, m, x) = (c[0], c[1], c[2]);
        var map = NArr(n);
        var k = NN;
        c = NList;
        WriteLine(Contest(n, m, x, map, k, c));
    }
    static long Contest(int n, int m, int x, int[][] map, int k, int[] c)
    {
        var counts = new int[n];
        foreach (var ci in c) if (ci > 0) ++counts[ci - 1];
        for (var i = counts.Length - 2; i >= 0; --i) counts[i] += counts[i + 1];
        var glist = new List<Pair>[m];
        for (var i = 0; i < glist.Length; ++i) glist[i] = new List<Pair>();
        foreach (var p in map) glist[p[1] - 1].Add(new Pair(p[1] - 1, p[0]));
        for (var i = 0; i < glist.Length; ++i) glist[i].Sort((l, r) => r.Value.CompareTo(l.Value));

        var tree = new AvlTree<Pair>();
        for (var g = 0; g < glist.Length; ++g) foreach (var v in glist[g]) tree.Insert(v);
        var tree2 = new PriorityQueue<int, int>();
        var ans = 0L;
        for (var i = 0; i < n; ++i)
        {
            if (tree.GetCount() > 0 && tree2.Count > 0)
            {
                var newpeek = tree.ElementAt(tree.GetCount() - 1);
                var newv = x + newpeek.Value;
                var oldv = tree2.Peek();
                if (newv > oldv)
                {
                    ans += (long)counts[i] * newv;
                    tree.Delete(newpeek);
                    for (var j = 1; j < glist[newpeek.Genre].Count; ++j)
                    {
                        tree.Delete(glist[newpeek.Genre][j]);
                        tree2.Enqueue(glist[newpeek.Genre][j].Value, - glist[newpeek.Genre][j].Value);
                    }
                }
                else
                {
                    ans += (long)counts[i] * tree2.Dequeue();
                }
            }
            else if (tree.GetCount() > 0)
            {
                var newpeek = tree.ElementAt(tree.GetCount() - 1);
                ans += (long)counts[i] * (x + newpeek.Value);
                tree.Delete(newpeek);
                for (var j = 1; j < glist[newpeek.Genre].Count; ++j)
                {
                    tree.Delete(glist[newpeek.Genre][j]);
                    tree2.Enqueue(glist[newpeek.Genre][j].Value, - glist[newpeek.Genre][j].Value);
                }
            }
            else
            {
                ans += (long)counts[i] * tree2.Dequeue();
            }
        }
        return ans;
    }
    public class Pair : IComparable<Pair>
    {
        public int Genre;
        public int Value;
        public Pair(int g, int v)
        {
            Genre = g;
            Value = v;
        }
        int IComparable<Pair>.CompareTo(Pair other)
        {
            var d = Value.CompareTo(other.Value);
            if (d != 0) return d;
            return Genre.CompareTo(other.Genre);
        }
    }
    public class AvlTree<T> where T: IComparable<T>
    {
        private class Node<U> where U: IComparable<U>
        {
            public U Value;
            public Node<U> Lc = null;
            public Node<U> Rc = null;
            public int Height;
            public int Count;
            public int CCount;
            public Node(int height, U value)
            {
                Height = height;
                Count = 1;
                CCount = 1;
                Value = value;
            }
        }
        private Node<T> root = null;
        static int GetHeight(Node<T> t)
        {
            return t == null ? 0 : t.Height;
        }
        static int GetCount(Node<T> t)
        {
            return t == null ? 0 : t.Count;
        }
        static int GetBalance(Node<T> t)
        {
            return GetHeight(t.Lc) - GetHeight(t.Rc);
        }
        static void Recalc(Node<T> t)
        {
            if (t == null) return;
            t.Height = 1 + Math.Max(GetHeight(t.Lc), GetHeight(t.Rc));
            t.Count = t.CCount + GetCount(t.Lc) + GetCount(t.Rc);
        }
        static Node<T> RotateLeft(Node<T> t)
        {
            Node<T> u = t.Rc;
            Node<T> t2 = u.Lc;
            u.Lc = t;
            t.Rc = t2;
            Recalc(t);
            Recalc(u);
            return u;
        }
        static Node<T> RotateRight(Node<T> t)
        {
            Node<T> u = t.Lc;
            Node<T> t2 = u.Rc;
            u.Rc = t;
            t.Lc = t2;
            Recalc(t);
            Recalc(u);
            return u;
        }
        static Node<T> RotateLR(Node<T> t)
        {
            t.Lc = RotateLeft(t.Lc);
            return RotateRight(t);
        }
        static Node<T> RotateRL(Node<T> t)
        {
            t.Rc = RotateRight(t.Rc);
            return RotateLeft(t);
        }
        static Node<T> BalanceLeft(Node<T> t)
        {
            if (GetBalance(t) > 1)
            {
                if (GetBalance(t.Lc) < 0) t = RotateLR(t);
                else t = RotateRight(t);
            }
            Recalc(t);
            return t;
        }
        static Node<T> BalanceRight(Node<T> t)
        {
            if (GetBalance(t) < -1)
            {
                if (GetBalance(t.Rc) > 0) t = RotateRL(t);
                else t = RotateLeft(t);
            }
            Recalc(t);
            return t;
        }
        /// <summary>valueを挿入する</summary>
        public void Insert(T value)
        {
            root = Insert(root, value);
        }
        Node<T> Insert(Node<T> cur, T value)
        {
            if (cur == null)
            {
                return new Node<T>(1, value);
            }
            var d = value.CompareTo(cur.Value);
            if (d < 0)
            {
                cur.Lc = Insert(cur.Lc, value);
                return BalanceLeft(cur);
            }
            else if (d > 0)
            {
                cur.Rc = Insert(cur.Rc, value);
                return BalanceRight(cur);
            }
            else
            {
                ++cur.CCount;
                Recalc(cur);
                return cur;
            }
        }
        /// <summary>valueを削除する 存在しない場合はなにもしない</summary>
        public void Delete(T value)
        {
            root = Delete(root, value);
        }
        Node<T> Delete(Node<T> cur, T value)
        {
            if (cur == null) return null;
            var d = value.CompareTo(cur.Value);
            if (d < 0)
            {
                cur.Lc = Delete(cur.Lc, value);
                return BalanceRight(cur);
            }
            else if (d > 0)
            {
                cur.Rc = Delete(cur.Rc, value);
                return BalanceLeft(cur);
            }
            else
            {
                --cur.CCount;
                if (cur.CCount == 0)
                {
                    if (cur.Lc != null)
                    {
                        Node<T> del = null;
                        var max = DeleteMax(cur.Lc, ref del);
                        cur.Lc = max;
                        cur.Value = del.Value;
                        cur.CCount = del.CCount;
                        return BalanceRight(cur);
                    }
                    else
                    {
                        return cur.Rc;
                    }
                }
                else
                {
                    Recalc(cur);
                    return cur;
                }
            }
        }
        Node<T> DeleteMax(Node<T> t, ref Node<T> del)
        {
            if (t.Rc == null)
            {
                del = t;
                return t.Lc;
            }
            else
            {
                var max = DeleteMax(t.Rc, ref del);
                t.Rc = max;
                return BalanceLeft(t);
            }
        }
        /// <summary>小さいほうからpos番目の要素を取得する</summary>
        public T ElementAt(int pos)
        {
            if (pos < 0 || pos >= GetCount(root)) return default;
            var t = ElementAt(root, pos);
            return t.Value;
        }
        /// <summary>小さいほうからpos番目の要素を取得する</summary>
        public T ElementAt(int pos, T defaultValue)
        {
            if (pos < 0 || pos >= GetCount(root)) return defaultValue;
            return ElementAt(pos);
        }
        Node<T> ElementAt(Node<T> cur, int pos)
        {
            if (pos < GetCount(cur.Lc)) return ElementAt(cur.Lc, pos);
            if (pos < GetCount(cur.Lc) + cur.CCount) return cur;
            if (pos < cur.Count) return ElementAt(cur.Rc, pos - GetCount(cur.Lc) - cur.CCount);
            return null;
        }
        public void Debug()
        {
            if (root == null) return;
            Console.WriteLine($"root val:{root.Value}, CCount:{root.CCount}, Count:{root.Count}");
            Debug(root.Value, root.Lc);
            Debug(root.Value, root.Rc);
        }
        void Debug(T pval, Node<T> cur)
        {
            if (cur == null) return;
            Console.WriteLine($"{pval} -> val:{cur.Value}, CCount:{cur.CCount}, Count:{cur.Count}");
            Debug(cur.Value, cur.Lc);
            Debug(cur.Value, cur.Rc);
        }
        /// <summary>value以上でもっとも小さい値とその場所を返却する</summary>
        public T LowerBound(T value, ref int index)
        {
            var cur = root;
            T ans = default;
            var add = 0;
            index = GetCount(root);
            while (cur != null)
            {
                if (value.CompareTo(cur.Value) <= 0)
                {
                    ans = cur.Value;
                    index = add + GetCount(cur.Lc);
                    cur = cur.Lc;
                }
                else
                {
                    add += GetCount(cur.Lc) + cur.CCount;
                    cur = cur.Rc;
                }
            }
            return ans;
        }
        /// <summary>要素の個数を求める</summary>
        public int GetCount()
        {
            return GetCount(root);
        }
    }
}