#include <bits/stdc++.h>
using namespace std;
int times[100003];
long long bit[100003];
long long sum[100003];
vector<int> K;
int n, m, k;
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);
    int j = a;
    while (j < n + 1) {
      times[j]++;
      sum[j] += c;
      bit[j] += a;
      j += (j & -j);
    }
    j = b + 1;
    while (j < n + 1) {
      times[j]--;
      sum[j] -= c;
      bit[j] -= a;
      j += (j & -j);
    }
  }
  long long fin = 0;
  for (int i = 0; i < k; i++) {
    int x;
    scanf("%d", &x);
    long long ans = 0, t = 0, b = 0;
    int j = x;
    while (j > 0) {
      ans += sum[j];
      t += times[j];
      b += bit[j];
      j -= (j & -j);
    }
    ans += (x * t) - b;
    fin += ans;
  }
  cout << fin << endl;
  return 0;
}
