#include <bits/stdc++.h>
using namespace std;
int a[111111], b[111111], c[111111], n, m, K;
int main() {
  scanf("%d%d%d", &n, &m, &K);
  for (int i = 0; i < m; ++i) scanf("%d%d%d", a + i, b + i, c + i);
  long long result = 0;
  for (int i = 0; i < K; ++i) {
    int cell;
    scanf("%d", &cell);
    for (int j = 0; j < m; ++j)
      if (cell >= a[j] && cell <= b[j]) {
        result += cell - a[j] + c[j];
      }
  }
  cout << result << endl;
  return 0;
}
