import sys
input = sys.stdin.readline
from bisect import bisect_left
N,M=map(int,input().split())
L=[-(1<<60)]+list(map(int,input().split()))+[1<<60]
FBW=[list(map(int,input().split())) for _ in range(M)]
ans=0

for f,b,w in FBW:
    i = bisect_left(L, f)
    if L[i]==f:
        ans += w
    else:
        ans += max(b, w-(f-L[i-1]), w-(L[i]-f))
print(ans)