#int(input())
#map(int, input().split())
#list(map(int, input().split()))

N, M = map(int, input().split())
L = list(map(int, input().split()))
F = [0] * M
for i in range(M):
    F[i] = list(map(int, input().split()))

ans = 0
import bisect

for i in range(M):
    f, b, w = F[i]
    t = bisect.bisect(L, f)
    if t == 0:
        ans += max(b, w-abs(f-L[0]))
    elif t == N:
        ans += max(b, w-abs(f-L[-1]))
    else:
        ans += max(b, w-abs(f-L[t]), w-abs(f-L[t-1]))

print(ans)