#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long a[(long long)1e5 + 10];
long long b[(long long)1e5 + 10];
long long c[(long long)1e5 + 10];
long long d[(long long)1e5 + 10];
int main() {
  cin >> n >> m >> k;
  for (long long i = 0; i < m; i++) {
    cin >> a[i] >> b[i] >> c[i];
  }
  for (long long i = 0; i < k; i++) {
    cin >> d[i];
  }
  long long sum = 0;
  for (long long i = 0; i < k; i++) {
    for (long long j = 0; j < m; j++) {
      if (a[j] <= d[i] && d[i] <= b[j]) {
        sum += c[j] + d[i] - a[j];
      }
    }
  }
  cout << sum << endl;
  return 0;
}
