#include <bits/stdc++.h>
using namespace std;
const int maxn = 100005;
int a[maxn], b[maxn], c[maxn];
int main() {
  int n, m, k;
  while (scanf("%d%d%d", &n, &m, &k) != EOF) {
    for (int i = 0; i < m; i++) {
      scanf("%d%d%d", &a[i], &b[i], &c[i]);
    }
    long long ans = 0;
    for (int step = 0; step < k; step++) {
      int tmp;
      scanf("%d", &tmp);
      for (int i = 0; i < m; i++) {
        if (tmp < a[i] || tmp > b[i]) continue;
        ans += c[i] + tmp - a[i];
      }
    }
    printf("%I64d\n", ans);
  }
  return 0;
}
