#include <bits/stdc++.h>
using namespace std;
const int nmax = 1e5 + 42;
int n, m, k;
long long pref[nmax];
long long add[nmax], rem[nmax];
long long val[nmax];
int main() {
  scanf("%i%i%i", &n, &m, &k);
  int l, r, x, p;
  for (int i = 1; i <= m; i++) {
    scanf("%i%i%i", &l, &r, &x);
    x--;
    pref[l] += x;
    pref[r + 1] -= x;
    add[l]++;
    add[r + 1]--;
    rem[r + 1] += (r - l + 1);
  }
  long long sum = 0, add_now = 0;
  for (int i = 1; i <= n; i++) {
    add_now = add_now + add[i];
    sum = sum + pref[i] + add_now - rem[i];
    val[i] = sum;
  }
  long long ans = 0;
  for (int i = 1; i <= k; i++) {
    scanf("%i", &p);
    ans = ans + val[p];
  }
  printf("%I64d\n", ans);
  return 0;
}
