#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
int n, m, k;
int main() {
  cin >> n >> m >> k;
  vector<int> a(m), b(m), c(m);
  for (int i = 0; i < m; i++) cin >> a[i] >> b[i] >> c[i];
  long long s = 0;
  for (int i = 0; i < k; i++) {
    int v;
    cin >> v;
    for (int i = 0; i < m; i++) {
      if (v < a[i] || b[i] < v) continue;
      s += (long long)v - a[i] + c[i];
    }
  }
  cout << s << endl;
}
