#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 2;
long long n, m, k, a[N], b[N], c[N], p[N], ans;
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < m; i++) cin >> a[i] >> b[i] >> c[i];
  for (int i = 0; i < k; i++) cin >> p[i];
  for (int i = 0; i < m; i++)
    for (int j = 0; j < k; j++)
      if (p[j] <= b[i] && p[j] >= a[i]) ans += c[i] + p[j] - a[i];
  cout << ans;
  return 0;
}
