#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=998244353;
ll inf=1009999999999999990;
int main(){
    ll n,m;
    cin >> n >> m;
    vector<ll>l(n+1);
    l[0]=-inf;
    for (ll i = 0; i < n; i++)
    {
        cin >> l[i+1];
    }
    l.push_back(inf);
    vector<ll>f(n),b(m),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++)
    {
        ll v=lower_bound(l.begin(),l.end(),f[i])-l.begin();
        ll x=min(f[i]-l[v-1],l[v]-f[i]);
        if (b[i]+x<w[i])
        {
            ans+=w[i]-x;
        }else{
            ans+=b[i];
        }
    }
    cout << ans << endl;
}