#include <bits/stdc++.h>
using namespace std;
long long Left[100005], Right[100005], init[100005];
int main() {
  int n, m, k;
  while (cin >> n >> m >> k) {
    for (int i = 0; i < m; i++) {
      cin >> Left[i] >> Right[i] >> init[i];
    }
    long long ans = 0;
    while (k--) {
      long long in;
      cin >> in;
      for (int i = 0; i < m; i++) {
        if (in < Left[i] || in > Right[i]) {
          continue;
        }
        ans += in - Left[i] + init[i];
      }
    }
    cout << ans << endl;
  }
  return 0;
}
