#include <bits/stdc++.h>
using namespace std;
const int maxN = 100100;
int a[maxN], b[maxN], c[maxN];
int main() {
  int n, m, k, x;
  long long res = 0;
  cin >> n >> m >> k;
  for (int i = 0; i < (m); ++i) cin >> a[i] >> b[i] >> c[i];
  for (int i = 0; i < (k); ++i) {
    cin >> x;
    for (int j = 0; j < (m); ++j)
      if (a[j] <= x && x <= b[j]) res += c[j] + x - a[j];
  }
  cout << res << endl;
  return 0;
}
