using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        Console.SetOut(sw);
        Solve();
        Console.Out.Flush();
    }
    static void Solve()
    {
        var N = sc.ReadInt();
        var M = sc.ReadInt();
        var A = sc.ReadIntArray(N);
        Array.Sort(A);
        var pq = new PriorityQueue<Tuple<int, int>>(N, false);
        foreach (var g in A.GroupBy(a => a))
        {
            pq.Enqueue(Tuple.Create(g.Key, g.Count()));
        }
        for (int i = 0; i < M; i++)
        {
            var b = sc.ReadInt();
            var c = sc.ReadInt();
            var insertCount = 0;
            while (b > 0 && pq.Peek().Item1 < c)
            {
                var t = pq.Dequeue();
                var prevValue = t.Item1;
                var prevCount = t.Item2;
                if (prevCount > b)
                {
                    pq.Enqueue(Tuple.Create(prevValue, prevCount - b));
                    insertCount += b;
                    break;
                }
                else
                {
                    insertCount += prevCount;
                    b -= prevCount;
                }
            }
            if (insertCount > 0) pq.Enqueue(Tuple.Create(c, insertCount));
        }
        var ans = 0l;
        while (pq.Count > 0)
        {
            var t = pq.Dequeue();
            ans += (long)t.Item1 * t.Item2;
        }
        Console.WriteLine(ans);
    }
    // Comparison<T> f = (x, y) => x.CompareTo(y);
    // Comparer<T>.Create(f)
    class PriorityQueue<T>
    {
        public readonly T[] Array;
        public readonly bool Greater;
        public int Count { get; private set; } = 0;
        private IComparer<T> Cmp;
        public PriorityQueue(int capacity, bool greater = true, IComparer<T> cmp = null)
        {
            this.Cmp = cmp;
            if (cmp == null)
            {
                this.Cmp = Comparer<T>.Default;
            }
            this.Array = new T[capacity];
            this.Greater = greater;
        }

        public void Enqueue(T item)
        {
            this.Array[this.Count] = item;
            this.Count += 1;
            this.UpHeap();
        }

        public T Dequeue()
        {
            this.Swap(0, this.Count - 1);
            this.Count -= 1;
            this.DownHeap();

            return this.Array[this.Count];
        }

        public T Peek()
        {
            return this.Array[0];
        }

        private void UpHeap()
        {
            var n = this.Count - 1;
            while (n != 0)
            {
                var parent = (n - 1) / 2;

                if (this.Compare(this.Array[n], this.Array[parent]) > 0)
                {
                    this.Swap(n, parent);
                    n = parent;
                }
                else
                {
                    break;
                }
            }
        }

        private void DownHeap()
        {
            var parent = 0;
            while (true)
            {
                var child = 2 * parent + 1;
                if (child > this.Count - 1) break;

                if (child < this.Count - 1 && this.Compare(this.Array[child], this.Array[child + 1]) < 0)
                {
                    child += 1;
                }

                if (this.Compare(this.Array[parent], this.Array[child]) < 0)
                {
                    this.Swap(parent, child);
                    parent = child;
                }
                else
                {
                    break;
                }
            }
        }

        private int Compare(T a, T b)
        {
            var c = this.Cmp.Compare(a, b);
            if (!this.Greater)
            {
                c = -c;
            }
            return c;
        }

        private void Swap(int a, int b)
        {
            var tmp = this.Array[a];
            this.Array[a] = this.Array[b];
            this.Array[b] = tmp;
        }
    }
    static Scanner sc = new Scanner();
}
class Scanner
{
    string[] S = new string[0];
    int Index = 0;
    char[] Separators = new char[] { ' ' };

    public string Next()
    {
        if (this.Index < this.S.Length) return this.S[this.Index++];
        var line = "";
        while (line == "") line = Console.ReadLine();
        this.S = line.Split(this.Separators, StringSplitOptions.RemoveEmptyEntries);
        if (this.S.Length == 0) return this.Next();
        this.Index = 0;
        return this.S[this.Index++];
    }
    public string ReadStr()
    {
        return this.Next();
    }
    public char ReadChar()
    {
        return this.Next()[0];
    }
    public int ReadInt()
    {
        return int.Parse(this.Next());
    }
    public uint ReadUInt()
    {
        return uint.Parse(this.Next());
    }
    public long ReadLong()
    {
        return long.Parse(this.Next());
    }
    public double ReadDouble()
    {
        return double.Parse(this.Next());
    }
    public Tuple<int, int> ReadTup(int add = 0)
    {
        return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add);
    }
    public Tuple<long, long> ReadTupLong(int add = 0)
    {
        return Tuple.Create(this.ReadLong() + add, this.ReadLong() + add);
    }
    public Tuple<int, int, int> ReadTup3(int add = 0)
    {
        return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add);
    }
    public Tuple<int, int, int, int> ReadTup4(int add = 0)
    {
        return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add);
    }
    public int[] ReadIntArray(int n)
    {
        var array = new int[n];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = this.ReadInt();
        }
        return array;
    }
    public long[] ReadLongArray(int n)
    {
        var array = new long[n];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = this.ReadLong();
        }
        return array;
    }
    public double[] ReadDoubleArray(int n)
    {
        var array = new double[n];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = this.ReadDouble();
        }
        return array;
    }
    public char[] ReadCharArray(int n)
    {
        var array = new char[n];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = this.ReadChar();
        }
        return array;
    }
    public string[] ReadStrArray(int n)
    {
        var array = new string[n];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = this.ReadStr();
        }
        return array;
    }
    public Tuple<long, long>[] ReadTupLongArray(int n, int add = 0)
    {
        var array = new Tuple<long, long>[n];
        for (int i = 0; i < n; i++)
        {
            array[i] = this.ReadTupLong(add);
        }
        return array;
    }
    public Tuple<int, int>[] ReadTupArray(int n, int add = 0)
    {
        var array = new Tuple<int, int>[n];
        for (int i = 0; i < n; i++)
        {
            array[i] = this.ReadTup(add);
        }
        return array;
    }
    public Tuple<int, int, int>[] ReadTup3Array(int n, int add = 0)
    {
        var array = new Tuple<int, int, int>[n];
        for (int i = 0; i < n; i++)
        {
            array[i] = this.ReadTup3(add);
        }
        return array;
    }
    public Tuple<int, int, int, int>[] ReadTup4Array(int n, int add = 0)
    {
        var array = new Tuple<int, int, int, int>[n];
        for (int i = 0; i < n; i++)
        {
            array[i] = this.ReadTup4(add);
        }
        return array;
    }
}


Measured memory_bytes: 41676