#include <bits/stdc++.h>
using namespace std;
const long double PI = 3.1415926535897932384626433832795029L;
bool solve(int testNumber) {
  int n, m, k;
  if (scanf("%d %d %d", &n, &m, &k) == EOF) return false;
  long long sum = 0;
  vector<int> from(m), to(m), base(m);
  for (int i = 0; i < m; i++) scanf("%d %d %d", &from[i], &to[i], &base[i]);
  while (k--) {
    int pos;
    scanf("%d", &pos);
    for (int i = 0; i < m; i++)
      if (pos >= from[i] and pos <= to[i]) sum += base[i] + pos - from[i];
  }
  printf("%lld\n", sum);
  return true;
}
int main() {
  for (int i = 1; solve(i); i++)
    ;
  return 0;
}
