#include <bits/stdc++.h>
using namespace std;
int n, m, k, a[100001], b[100001], c[100001];
long long ans;
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < m; ++i) {
    scanf("%d%d%d", &a[i], &b[i], &c[i]);
  }
  ans = 0;
  int x;
  for (int i = 0; i < k; ++i) {
    cin >> x;
    for (int j = 0; j < m; ++j) {
      if (a[j] <= x && x <= b[j]) {
        ans += c[j] + x - a[j];
      }
    }
  }
  cout << ans;
  return 0;
}
