#include <bits/stdc++.h>
using namespace std;
const int M = 100005;
int a[M], b[M], x[M];
int n, m, k;
long long cnt(int t) {
  long long ans = 0;
  for (int i = 0; i < m; i++) {
    if (b[i] < t || a[i] > t) continue;
    ans += t - a[i] + x[i];
  }
  return ans;
}
int main(int argc, char **argv) {
  cin >> n >> m >> k;
  for (int i = 0; i < m; i++) cin >> a[i] >> b[i] >> x[i];
  int t;
  long long sum = 0;
  for (int i = 0; i < k; i++) {
    cin >> t;
    sum += cnt(t);
  }
  cout << sum;
  return 0;
}
