#include <bits/stdc++.h>
using namespace std;
int n, m, k, l[200011], r[200011], x[200011], y;
long long ans[200011];
vector<int> cl[200011], op[200011];
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= m; ++i) {
    scanf("%d%d%d", &l[i], &r[i], &x[i]);
    op[l[i]].push_back(i);
    cl[r[i] + 1].push_back(i);
  }
  long long cur = 0;
  int cnt = 0;
  for (int i = 1; i <= n; ++i) {
    for (int j = 0; j < op[i].size(); ++j) cur += -l[op[i][j]] + x[op[i][j]];
    for (int j = 0; j < cl[i].size(); ++j) cur -= -l[cl[i][j]] + x[cl[i][j]];
    cnt += (int)op[i].size() - (int)cl[i].size();
    ans[i] = cnt * 1ll * i + cur;
  }
  long long ansx = 0;
  for (int i = 1; i <= k; ++i) scanf("%d", &y), ansx += ans[y];
  cout << ansx;
}
