#include <bits/stdc++.h>
using namespace std;
unsigned long long int o = 0, n, m, k, l[100000], r[100000], h[100000], ask;
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < m; i++) {
    cin >> l[i] >> r[i] >> h[i];
  }
  for (int i = 0; i < k; i++) {
    cin >> ask;
    for (int j = 0; j < m; j++) {
      if (ask <= r[j] && ask >= l[j]) {
        o += h[j] + ask - l[j];
      }
    }
  }
  cout << o;
  return 0;
}
