#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  long long pl[n + 1], prog[n + 1], ans[n];
  for (int i = 0; i < n; i++) {
    pl[i] = 0;
    prog[i] = 0;
  }
  for (int i = 0; i < m; i++) {
    int l, r, x;
    cin >> l >> r >> x;
    pl[l - 1]++;
    pl[r - 1]--;
    prog[l - 1] += x;
    prog[r] -= x + r - l;
  }
  ans[0] = prog[0];
  for (int i = 1; i < n; i++) {
    pl[i] += pl[i - 1];
    prog[i] += prog[i - 1];
    prog[i] += pl[i - 1];
    ans[i] = ans[i - 1] + prog[i];
  }
  long long anss = 0;
  for (int i = 0; i < k; i++) {
    int aa;
    cin >> aa;
    anss += prog[aa - 1];
  }
  cout << anss << endl;
  return 0;
}
