#include <bits/stdc++.h>
using namespace std;
struct ladder {
  long long beg, end, h;
};
int n, k, m;
long long ya[100100], q[110];
ladder l[100100];
int main() {
  cin >> n >> m >> k;
  for (int i = 1; i <= m; i++) cin >> l[i].beg >> l[i].end >> l[i].h;
  for (int i = 1; i <= k; i++) cin >> q[i];
  for (int i = 1; i <= k; i++)
    for (int j = 1; j <= m; j++)
      if (q[i] >= l[j].beg && q[i] <= l[j].end) {
        ya[q[i]] += l[j].h + q[i] - l[j].beg;
      }
  long long sum = 0;
  for (int i = 1; i <= k; i++) {
    sum += ya[q[i]];
  }
  cout << sum;
  return 0;
}
