import bisect
N, M = map(int, input().split())
L = list(map(int, input().split()))
FBW = [list(map(int, input().split())) for _ in range(M)]
ans = 0
for f, b, w in FBW:
    pos = bisect.bisect_left(L, f)
    if pos<N:
        if L[pos]==f:
            ans += w
        else:
            c = L[pos]-f
            if pos>0:
                c = min(c, f-L[pos-1])
            ans += max(b, w-c)
    else:
        c = f-L[pos-1]
        ans += max(b, w-c)
print(ans)