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

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            new ABC127().SolveD(new ConsoleInput(Console.In, ' '));
        }
    }

    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; }
    }
  class ABC127
  {
    public void SolveD(ConsoleInput cin)
        {
            var n = cin.ReadInt;
            var m = cin.ReadInt;
            var A = cin.ReadIntArray(n);
            var ChangeList = new List<BandC>();
            for (int i = 0; i < m; i++)
            {
                ChangeList.Add(new BandC(cin.ReadInt, cin.ReadInt));
            }
            var SortedList = ChangeList.OrderByDescending(x => x.c);
            var SortedA = A.OrderBy(x => x).ToArray();
            var D = new int[n];
            //最大n回のループ
            int index = 0;
            var exit = false;
            foreach (var x in SortedList)
            {
                for (int i = 0; i < x.b; i++)
                {
                    D[index] = x.c;
                    index++;
                    if (index >= n)
                    {
                        exit = true;
                        break;
                    }
                }
                if (exit) break;
            }
           long sum = 0;
            for(int i = 0; i < n; i++)
            {
                if (SortedA[i] > D[i]) sum += SortedA[i];
                else sum += D[i];
            }
            WriteLine(sum);
            ReadLine();
        }
    
  }
  public class BandC
    {
        public int b { get; set; }
        public int c { get; set; }
        public BandC(int _b, int _c)
        {
            b = _b;
            c = _c;
        }
    }
}


Measured memory_bytes: 33596