using System.Collections.Generic;
using static System.Math;
using System;

public class Hello
{
    static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var n = int.Parse(line[0]);
        var m = int.Parse(line[1]);
        line = Console.ReadLine().Trim().Split(' ');
        var a = Array.ConvertAll(line, int.Parse);
        getAns(n, m, a);
    }
    static void getAns(int n, int m, int[] a)
    {
        var ans = 0L;
        for (int i = 0; i < m; i++)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            var f = int.Parse(line[0]);
            var b = int.Parse(line[1]);
            var w = int.Parse(line[2]);
            var p = LowerBound(a, f);
            if (p != n && a[p] == f) { ans += w; continue; }
            else ans += b;
            int c;
            if (p == n) c = f - a[n - 1];
            else if (p == 0) c = a[0] - f;
            else
            {
                var c1 = a[p] - f;
                var c2 = f - a[p - 1];
                c = Min(c1, c2);
            }
            ans += Max(0, w - b - c);
        }
        Console.WriteLine(ans);
    }
    static int LowerBound<T>(T[] arr, int start, int end, T value, IComparer<T> comparer)
    {
        var low = start;
        var high = end;
        while (low < high)
        {
            var mid = (high + low) / 2;
            if (comparer.Compare(arr[mid], value) < 0) low = mid + 1;
            else high = mid;
        }
        return low;
    }
    static int LowerBound<T>(T[] arr, T value) where T : IComparable
       => LowerBound(arr, 0, arr.Length, value, Comparer<T>.Default);
}