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

namespace AtCoder
{
    class Program
    {
        private int N, M;
        private int[] A;
        private int[] B, C;
        static void Main(string[] args)
        {
            new Program().Solve();
        }

        public void Solve()
        {
            var sc = new Scanner();
            N = sc.NextInt();
            M = sc.NextInt();
            A = sc.IntArray();
            B = new int[M];
            C = new int[M];
            for (int i = 0; i < M; i++)
            {
                B[i] = sc.NextInt();
                C[i] = sc.NextInt();

            }

            Array.Sort(A, (a, b) => a.CompareTo(b));

            int[] tmp = (new int[M]).Select((i, index) => index).ToArray();

            Array.Sort(tmp, (a, b) => -C[a].CompareTo(C[b]));

            int ind = 0;
            long sum = 0;
            foreach (int i in tmp)
            {
                bool flag = false;
                for (int j = 0; j < B[i] && ind < N; j++, ind++)
                {
                    if (A[ind] < C[i])
                    {
                        A[ind] = C[i];
                    }
                    else
                    {
                        break;
                    }
                    sum += A[ind];
                }


            }

            for (int i = ind; i < N; i++)
            {
                sum += A[i];
            }
            Console.WriteLine(sum);
        }
    }
}




class Scanner
{
    public Scanner()
    {
        _stream = new StreamReader(Console.OpenStandardInput());
        _pos = 0;
        _line = new string[0];
    }

    const char Separator = ' ';
    private readonly StreamReader _stream;
    private int _pos;
    private string[] _line;

    #region スペース区切りで取得

    public string Next()
    {
        if (_pos >= _line.Length)
        {
            _line = _stream.ReadLine().Split(Separator);
            _pos = 0;
        }

        return _line[_pos++];
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public double NextDouble()
    {
        return double.Parse(Next());
    }

    #endregion

    #region 型変換

    private int[] ToIntArray(string[] array)
    {
        var result = new int[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = int.Parse(array[i]);
        }

        return result;
    }

    private long[] ToLongArray(string[] array)
    {
        var result = new long[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = long.Parse(array[i]);
        }

        return result;
    }

    private double[] ToDoubleArray(string[] array)
    {
        var result = new double[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = double.Parse(array[i]);
        }

        return result;
    }

    #endregion

    #region 配列取得

    public string[] Array()
    {
        if (_pos >= _line.Length)
            _line = _stream.ReadLine().Split(Separator);

        _pos = _line.Length;
        return _line;
    }

    public int[] IntArray()
    {
        return ToIntArray(Array());
    }

    public long[] LongArray()
    {
        return ToLongArray(Array());
    }

    public double[] DoubleArray()
    {
        return ToDoubleArray(Array());
    }

    #endregion
}


Measured memory_bytes: 27200