#include <bits/stdc++.h>
using namespace std;
vector<int> K;
int n, m, k;
int Q[100002][3];
long long S[100002];
int main() {
  scanf("%d %d %d", &n, &m, &k);
  for (int i = 1; i <= m; i++) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    Q[i - 1][0] = a;
    Q[i - 1][1] = b;
    Q[i - 1][2] = c;
  }
  for (int i = 0; i < k; i++) {
    int x;
    scanf("%d", &x);
    K.push_back(x);
  }
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < k; j++) {
      if (K[j] >= Q[i][0] && K[j] <= Q[i][1]) {
        S[K[j]] += 1ll * (Q[i][2] + K[j] - Q[i][0]);
      }
    }
  }
  long long sum = 0;
  for (int i = 0; i < k; i++) sum += S[K[i]];
  cout << sum << endl;
  return 0;
}
