from bisect import bisect_left, bisect_right

n, m = map(int, input().split())
L = [-1 << 40] + list(map(int, input().split())) + [1 << 40]
ans = 0
for _ in range(m):
    f, b, w = map(int, input().split())
    p = bisect_left(L, f)
    dl = f - L[p - 1]
    dr = L[p] - f
    ans += max(b, w - min(dl, dr))
print(ans)