#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAX_N = 1e5 + 9;
vector<array<int, 3>> vc;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, m, k, u, v, w;
  cin >> n >> m >> k;
  while (m--) {
    cin >> u >> v >> w;
    vc.push_back({u, v, w});
  }
  ll ans = 0;
  while (k--) {
    cin >> u;
    for (auto i : vc)
      if (u >= i[0] && u <= i[1]) ans += (u - i[0]) + i[2];
  }
  cout << ans;
}
