#include <bits/stdc++.h>
using namespace std;
const int INF = 2e9;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> a(m + 1), b(m + 1), c(m + 1);
  for (int i = 1; i <= m; i++) {
    cin >> a[i] >> b[i] >> c[i];
  }
  long long sol = 0;
  for (int i = 1; i <= k; i++) {
    long long pos;
    cin >> pos;
    long long ans = 0;
    for (int j = 1; j <= m; j++) {
      if (pos >= a[j] && pos <= b[j]) {
        int diff = pos - a[j];
        diff += c[j];
        ans += diff;
      }
    }
    sol += ans;
  }
  cout << sol << '\n';
  return 0;
}
