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