#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int main() {
	int N, M;
	cin >> N >> M;
	vector<long long> L(N);
	for (int i = 0; i < N; i++) {
		cin >> L[i];
	}
	vector<long long> F(M), B(M), W(M);
	for (int i = 0; i < M; i++) {
		cin >> F[i] >> B[i] >> W[i];
	}
	long long answer = 0;
	for (int i = 0; i < M; i++) {
		int pos = lower_bound(L.begin(), L.end(), F[i]) - L.begin();
		long long subanswer = B[i];
		if (pos != N) {
			subanswer = max(subanswer, W[i] - (L[pos] - F[i]));
		}
		if (pos != 0) {
			subanswer = max(subanswer, W[i] - (F[i] - L[pos - 1]));
		}
		answer += subanswer;
	}
	cout << answer << endl;
	return 0;
}