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