import sys
#sys.setrecursionlimit(10 ** 6)
INF = float('inf')
MOD = 10**9 + 7
MOD2 = 998244353
from collections import defaultdict
def ceil(A,B):
    return -(-A//B)
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(sys.stdin.readline().rstrip())
    def IC(): return [int(c) for c in sys.stdin.readline().rstrip()]
    def MI(): return map(int, sys.stdin.readline().split())
    N,M = MI()
    L = LI()
    L = [-10**10] + L + [10**10]
    from bisect import bisect_left
    S = 0
    for i in range(M):
        F,B,W = MI()
        lake = bisect_left(L,F)
        C = min(abs(L[lake-1]-F),abs(L[lake]-F))
        S += max(B,W-C)
    print(S)
    return
solve()