#include <bits/stdc++.h>
using namespace std;
long long a[100000], b[100000], x[100000];
int main() {
  long long n, m, k, t;
  long long res = 0;
  cin >> n >> m >> k;
  for (int i = 0; i < m; ++i) cin >> a[i] >> b[i] >> x[i];
  for (int i = 0; i < k; ++i) {
    cin >> t;
    for (int j = 0; j < m; ++j) {
      if (t <= b[j] && t >= a[j]) {
        res += x[j] + t - a[j];
      }
    }
  }
  cout << res << endl;
  return 0;
}
