import sys
input = sys.stdin.readline
from bisect import *

N, M = map(int, input().split())
inf = 10 ** 18
L = [-inf] + list(map(int, input().split())) + [inf]
ans = 0
for i in range(M):
    F, B, W = map(int, input().split())
    ind = bisect_right(L, F)
    ans += max(B, W - min(L[ind] - F, F - L[ind - 1]))

print(ans)