#include <bits/stdc++.h>
using namespace std;
int main(void) {
  ios::sync_with_stdio(false);
  int n, m, k;
  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 ans = 0;
  while (k--) {
    int pos;
    cin >> pos;
    for (int i = 0; i < (m); ++i)
      if (a[i] <= pos && pos <= b[i]) ans += pos - a[i] + c[i];
  }
  cout << ans << endl;
  return 0;
}
