#include <bits/stdc++.h>
using namespace std;
int i, n, m, k, x;
long long rs, v[100005], a[100005], b[100005], c[100005];
int main() {
  ios_base::sync_with_stdio(0);
  cin >> n >> m >> k;
  for (i = 1; i <= m; ++i) cin >> a[i] >> b[i] >> c[i];
  while (k--) {
    cin >> x;
    for (i = 1; i <= m; ++i) {
      if (x < a[i] || x > b[i]) continue;
      v[x] += c[i] + (x - a[i]);
    }
  }
  for (i = 1; i <= n; ++i) rs += v[i];
  cout << rs << '\n';
  return 0;
}
