#include <bits/stdc++.h>
using namespace std;
int a[1000000] = {0};
int b[1000000] = {0};
struct node {
  int x, y, l;
};
node s[120000];
int p[20000] = {0};
int main() {
  iostream::sync_with_stdio(0);
  int n, m, k;
  cin >> n >> m >> k;
  int l = 0;
  while (m--) {
    node ss;
    cin >> ss.x >> ss.y >> ss.l;
    s[l++] = ss;
  }
  for (int i = 0; i < k; i++) {
    cin >> a[i];
  }
  sort(a, a + k);
  long long ans = 0;
  for (int i = 0; i < l; i++) {
    for (int j = 0; j < k; j++) {
      if (a[j] > s[i].y)
        break;
      else if (a[j] >= s[i].x) {
        ans += a[j] - s[i].x + s[i].l;
      }
    }
  }
  cout << ans << endl;
}
