#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int a[100000], b[100000], c[100000];
int d[100];
long long int e[100], g;
int main() {
  g = 0;
  ifstream in("test.txt");
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < m; i++) scanf("%d%d%d", &a[i], &b[i], &c[i]);
  for (int i = 0; i < k; i++) {
    scanf("%d", &d[i]);
    e[i] = 0;
  }
  for (int i = 0; i < k; i++)
    for (int j = 0; j < m; j++)
      if (d[i] >= a[j] && d[i] <= b[j]) {
        e[i] += (long long int)d[i] - a[j] + c[j];
      }
  for (int i = 0; i < k; i++) g += e[i];
  cout << g;
  return 0;
}
