#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, M;
  cin >> N >> M;
  vector<int> L(N);
  for (int i = 0; i < N; i++){
    cin >> L[i];
  }
  long long ans = 0;
  for (int i = 0; i < M; i++){
    int F, B, W;
    cin >> F >> B >> W;
    int p = lower_bound(L.begin(), L.end(), F) - L.begin();
    int tmp = B;
    if (p >= 1){
      tmp = max(tmp, W - (F - L[p - 1]));
    }
    if (p < N){
      tmp = max(tmp, W - (L[p] - F));
    }
    ans += tmp;
  }
  cout << ans << endl;
}