#include <bits/stdc++.h>
using namespace std;
struct ll {
  int l, r, c;
};
ll a[100000];
long long int b[100], s;
int d[100];
int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < m; i++) scanf("%d%d%d", &a[i].l, &a[i].r, &a[i].c);
  for (int i = 0; i < k; i++) scanf("%d", &d[i]);
  for (int i = 0; i < m; i++)
    for (int j = 0; j < k; j++)
      if (d[j] >= a[i].l && d[j] <= a[i].r) b[j] += a[i].c + d[j] - a[i].l;
  for (int i = 0; i < k; i++) s += b[i];
  cout << s << endl;
  return 0;
}
