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

namespace ABC127D
{
    public class Program
    {
        public static void Main(string[] args)
        {
            new Program().Solve(new ConsoleInput(Console.In, ' '));

            return;
        }

        public void Solve(ConsoleInput cin)
        {

            var N = cin.ReadInt;
            var M = cin.ReadInt;
            var A = cin.ReadIntArray(N);
            List<CardStock> cardStocks = new List<CardStock>();
            for (int i = 0; i < M; i++)
            {
                cardStocks.Add(new CardStock(){Maisu = cin.ReadInt, Kazu = cin.ReadInt});
            }

            cardStocks.Sort((a, b) => b.Kazu - a.Kazu);
            var changeArray  = new int[N];
            var index = 0;
            foreach (var cardStock in cardStocks)
            {
                for (long i = 0; i < cardStock.Maisu; i++)
                {
                    changeArray[index] = cardStock.Kazu;
                    if (index == N - 1)
                    {
                        break;
                    }
                    else
                    {
                        index++;
                    }
                }
                if (index == N - 1)
                {
                    break;
                }
            }

            Array.Sort(A);

            for(int i = 0; i < N; i++)
            {
                if(A[i] >= changeArray[i])
                {
                    break;
                }
                else
                {
                    A[i] = changeArray[i];
                }
            }

            long ans = 0;
            for (int i = 0; i < N; i++)
            {
                ans += (long)A[i];
            }

            Console.WriteLine(ans);

        }
        public class CardStock
        {
            public int Maisu {get; set;}
            public int Kazu {get; set;}
        }
    }

    public static class Extensions
    {
        public static string Reverse(this string sourse)
        {
            char[] chrAry = sourse.ToCharArray();
            Array.Reverse(chrAry);
            return new string(chrAry);
        }
    }

    public class ConsoleInput
    {
        private readonly System.IO.TextReader _stream;
        private char _separator = ' ';
        private Queue<string> inputStream;
        public ConsoleInput(System.IO.TextReader stream, char separator = ' ')
        {
            this._separator = separator;
            this._stream = stream;
            inputStream = new Queue<string>();
        }
        public string Read
        {
            get
            {
                if (inputStream.Count != 0) return inputStream.Dequeue();
                string[] tmp = _stream.ReadLine().Split(_separator);
                for (int i = 0; i < tmp.Length; ++i)
                    inputStream.Enqueue(tmp[i]);
                return inputStream.Dequeue();
            }
        }
        public string ReadLine { get { return _stream.ReadLine(); } }
        public int ReadInt { get { return int.Parse(Read); } }
        public long ReadLong { get { return long.Parse(Read); } }
        public double ReadDouble { get { return double.Parse(Read); } }
        public string[] ReadStrArray(long N) { var ret = new string[N]; for (long i = 0; i < N; ++i) ret[i] = Read; return ret; }
        public int[] ReadIntArray(long N) { var ret = new int[N]; for (long i = 0; i < N; ++i) ret[i] = ReadInt; return ret; }
        public long[] ReadLongArray(long N) { var ret = new long[N]; for (long i = 0; i < N; ++i) ret[i] = ReadLong; return ret; }
    }
}

Measured memory_bytes: 32084