n, m = map(int, input().split())
L = list(map(int, input().split()))

s, c = 0, 0
for _ in range(m):
    f, b, w = map(int, input().split())
    
    distance = min(abs(f - lake) for lake in L)

    if distance == 0:
        s += w
    else:
        cost = distance
        if w - cost > b:
            s += w
            c += cost
        else:
            s += b

print(s - c)