#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> P;
#define REP(i,n) for(int i=0;i<int(n);i++)

ll F[100010],B[100010],W[100010];

int main(void){
	cin.tie(nullptr);  ios_base::sync_with_stdio(false);
	ll i,j,k;

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

	ll ans=0;
	for(i=1;i<=M;i++){
		ll x=lower_bound(L.begin(),L.end(),F[i])-L.begin();

		if(F[i]==L[x]){
			ans+=W[i];
			continue;
		}
		if(x==0){
			if(L[0]-F[i]>=W[i]-B[i]){
				ans+=B[i];
				continue;
			}
			else{
				ans+=W[i]-(L[0]-F[i]);
				continue;
			}
		}

		if(x==N){
			if(F[i]-L[N-1]>=W[i]-B[i]){
				ans+=B[i];
				continue;
			}
			else{
				ans+=W[i]-F[i]+L[N-1];
			    continue;
			}
		}

		if(L[x]-F[i]<W[i]-B[i] || F[i]-L[x-1]<W[i]-B[i]){
			ans+=B[i]+max(W[i]-B[i]-L[x]+F[i],W[i]-B[i]-F[i]+L[x-1]);
		}else{
			ans+=B[i];
		}


	}

	cout << ans << endl;


	return 0;
}