from bisect import bisect_left
n,m = map(int,input().split())
l = list(map(int,input().split()))
ans = 0
for _ in range(m):
    f,b,w = map(int,input().split())
    i = bisect_left(l,f)
    c = 0 if i<n and l[i]==f else 10**9
    if i>0: c = min(c,f-l[i-1])
    if i<n: c = min(c,l[i]-f)
    ans += max(b,w-c)
print(ans)