#include <bits/stdc++.h>
using namespace std;
int main() {
  cout << fixed;
  cout.precision(9);
  vector<long long> l, r, x;
  int n, m, k;
  scanf("%i %i %i", &n, &m, &k);
  while (m--) {
    int ll, rr, xx;
    scanf("%i %i %i", &ll, &rr, &xx);
    l.push_back(ll);
    r.push_back(rr);
    x.push_back(xx);
  }
  long long res = 0;
  while (k--) {
    int b;
    scanf("%i", &b);
    for (size_t i = 0; i < l.size(); ++i) {
      if (b >= l[i] && b <= r[i]) {
        res += x[i] + b - l[i];
      }
    }
  }
  cout << res << endl;
  return 0;
}
