#include <bits/stdc++.h>
using namespace std;
const int N = 100000;
int a[N], b[N], c[N];
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  for (int i = 0; i < m; ++i) cin >> a[i] >> b[i] >> c[i];
  long long sum = 0;
  while (k--) {
    int x;
    cin >> x;
    for (int i = 0; i < m; ++i)
      if (x >= a[i] && x <= b[i]) sum += (c[i] + x - a[i]);
  }
  cout << sum;
  return 0;
}
