#include <bits/stdc++.h>
using namespace std;
const double PI = 2 * acos(0.0);
const long long MOD = 1e9 + 7;
struct compare {
  bool operator()(const int& l, const int& r) { return l > r; }
};
long long gcd(long long x, long long y) {
  return ((y == 0) ? x : gcd(y, x % y));
}
long long lcm(long long x, long long y) { return ((x * y) / gcd(x, y)); }
long long BMod(long long B, long long P, long long M) {
  long long R = 1;
  B = B % M;
  while (P) {
    if (P & 1) R = (R * B) % M;
    P >>= 1;
    B = (B * B) % M;
  }
  return R;
}
struct node {
  int x, y, z;
};
int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL);
  long long n, m, q, ans = 0, a, b, c, pos;
  cin >> n >> m >> q;
  vector<node> vec;
  for (int i = 1; i <= m; i++) {
    node name;
    cin >> name.x >> name.y >> name.z;
    vec.push_back(name);
  }
  while (q--) {
    cin >> pos;
    for (int i = 0; i < vec.size(); i++) {
      if (pos >= vec[i].x && pos <= vec[i].y) {
        ans += (pos - vec[i].x) + vec[i].z;
      }
    }
  }
  cout << ans << "\n";
  return 0;
}
