#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const int inf = (int)1e9;
struct pt {
  int l, r, x;
};
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  vector<pt> a(m);
  for (int i = 0; i < m; ++i) {
    scanf("%d %d %d", &a[i].l, &a[i].r, &a[i].x);
  }
  long long int res = 0;
  for (int i = 0; i < k; ++i) {
    int x;
    scanf("%d", &x);
    for (int i = 0; i < m; ++i) {
      if (a[i].l <= x && x <= a[i].r) {
        res += a[i].x + x - a[i].l;
      }
    }
  }
  cout << res;
  return 0;
}
