#include <bits/stdc++.h>
using namespace std;
int inf = 10000000;
int n, m, k;
vector<pair<pair<int, int>, int> > v;
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < m; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    v.push_back(pair<pair<int, int>, int>(pair<int, int>(a, b), c));
  }
  long long sum = 0LL;
  for (int i = 0; i < k; i++) {
    int b;
    cin >> b;
    for (int j = 0; j < v.size(); j++) {
      int start = v[j].first.first, end = v[j].first.second,
          cubes = v[j].second;
      if (b >= start && b <= end) sum += (long long)cubes + b - start;
    }
  }
  cout << sum << endl;
  cin >> n;
  return 0;
}
