#include <bits/stdc++.h>
using namespace std;
int A[100010];
int B[100010];
int C[100010];
int main() {
  int n;
  scanf("%d", &n);
  int m, k;
  scanf("%d%d", &m, &k);
  for (int i = 0; i < m; i++) {
    scanf("%d%d%d", A + i, B + i, C + i);
  }
  long long sum = 0;
  for (int i = 0; i < k; i++) {
    int take;
    scanf("%d", &take);
    for (int t = 0; t < m; t++) {
      if (take >= A[t] && take <= B[t]) sum += (C[t] + take - A[t]);
    }
  }
  printf("%I64d\n", sum);
  return 0;
}
