#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:256000000")
const int mxx = 100010;
using namespace std;
long long a[mxx];
long long b[mxx];
long long c[mxx];
int main() {
  int i, j, n, m, k;
  cin >> n >> m >> k;
  for (i = 1; i <= m; ++i) {
    cin >> a[i] >> b[i] >> c[i];
  }
  long long pos;
  long long res = 0, d;
  for (i = 1; i <= k; ++i) {
    cin >> pos;
    for (j = 1; j <= m; ++j) {
      if (pos >= a[j] && pos <= b[j]) {
        d = pos - a[j];
        res += (c[j] + d);
      }
    }
  }
  cout << res;
  return 0;
}
