#include <bits/stdc++.h>
using namespace std;
int main(int argc, char **argv) {
  int N, M, K;
  cin >> N >> M >> K;
  vector<pair<int, int> > S(M);
  vector<int> T(M);
  for (int i = (0); i < (M); ++i) cin >> S[i].first >> S[i].second >> T[i];
  long long res = 0;
  for (int i = (0); i < (K); ++i) {
    int p;
    cin >> p;
    for (int j = (0); j < (M); ++j)
      if (S[j].first <= p && p <= S[j].second) res += p - S[j].first + T[j];
  }
  cout << res << endl;
  return 0;
}
