#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
using ll = long long;

ll INF = 1000000000000000;

int main() {
    ll N, M;
    cin >> N >> M;
    vector<ll> L(N + 2);
    L[0] = -INF;
    for (ll i = 0; i < N; i++) {
        cin >> L[i + 1];
    }
    L[N + 1] = INF;
    vector<ll> F(M);
    vector<ll> B(M);
    vector<ll> W(M);
    for (ll i = 0; i < M; i++) {
        cin >> F[i] >> B[i] >> W[i];
    }

    ll ans = 0;
    for (ll i = 0; i < M; i++) {
        auto itr = lower_bound(L.begin(), L.end(), F[i]);
        ll val1 = *itr;
        itr--;
        ll val2 = *itr;
        ll min_dist = min(abs(val1 - F[i]), abs(val2 - F[i]));
        if (min_dist < W[i] - B[i]) {
            ans += W[i] - min_dist;
        } else {
            ans += B[i];
        }
    }
    cout << ans << endl;
}