#include <bits/stdc++.h>
using namespace std;

int main() {
  int N, M; cin >> N >> M;
  long long Ans = 0;
  vector<int> L(N); for (int &a : L) cin >> a;

  for (int i = 0; i < M; i++) {
    int F, B, W; cin >> F >> B >> W;
    int it = lower_bound(L.begin(), L.end(), F) - L.begin();
    if (it == 0) Ans += max(B, W - L.at(it) + F);
    else if (it == N) Ans += max(B, W - F + L.at(it - 1));
    else Ans += max(B, max( W - L.at(it) + F, W - F + L.at(it - 1)));
  }

  cout << Ans << endl;
}