#include <bits/stdc++.h>
using namespace std;
int a[100000], b[100000], c[100000];
int main() {
  int n, m, k;
  ios::sync_with_stdio(false);
  cin >> n >> m >> k;
  for (int i = 0; i < m; ++i) {
    cin >> a[i] >> b[i] >> c[i];
  }
  long long final = 0;
  for (int i = 0; i < k; ++i) {
    int pos;
    cin >> pos;
    long long ans = 0;
    for (int j = 0; j < m; ++j) {
      if (a[j] <= pos && pos <= b[j]) {
        ans += c[j] + (pos - a[j]);
      }
    }
    final += ans;
  }
  cout << final << endl;
  return 0;
}
