from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

N,M = map(int,input().split())
L = list(map(int,input().split()))
X = []
s = 0
for _ in range(M):
    f,b,w = map(int,input().split())
    s += b
    is_ok = lambda x: L[x]<=f
    if is_ok(N-1):
        x = N-1
        X.append(w-b-abs(L[x]-f))
        continue
    if not is_ok(0):
        X.append(w-b-abs(L[0]-f))
        continue
    y = N-1
    x = 0
    while y-x>1:
        mid = (y+x)//2
        if is_ok(mid):
            x = mid
        else:
            y = mid

    X.append(w-b-min(abs(L[x]-f),abs(L[y]-f)))
X.sort(reverse=True)
for x in X:
    if x<=0:
        break
    s += x
print(s)