#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int N, M;
ll L[101010], F[101010], B[101010], W[101010];

int main() {
  cin >> N >> M;
  for (int i = 0; i < N; i++) cin >> L[i];
  for (int i = 0; i < M; i++) cin >> F[i] >> B[i] >> W[i];
  ll ans = 0;
  for (int i = 0; i < M; i++) {
    int pos1 = lower_bound(L, L + N, F[i]) - L;
    if (pos1 == 0) {
      if (abs(L[pos1] - F[i]) < W[i] - B[i]) ans += W[i] - abs(L[pos1] - F[i]);
      else ans += B[i];
    } else if (pos1 == N) {
      if (abs(L[pos1 - 1] - F[i]) < W[i] - B[i]) ans += W[i] - abs(L[pos1 - 1] - F[i]);
      else ans += B[i];
    } else {
      if (min(abs(L[pos1] - F[i]), abs(L[pos1 - 1] - F[i])) < W[i] - B[i]) ans += W[i] - min(abs(L[pos1] - F[i]), abs(L[pos1 - 1] - F[i]));
      else ans += B[i];
    }
  }
  cout << ans << endl;
  return 0;
}