#include <bits/stdc++.h>
using namespace std;
const long long maxN = 1e5 + 7, MOD = 81409, inf = 1e9, N = 1e6 + 7;
long long n, m, k, a[maxN], x[maxN], y[maxN], z[maxN], ans, b[107];
int main() {
  scanf("%I64d%I64d%I64d", &n, &m, &k);
  for (long long i = 1; i <= m; i++) cin >> x[i] >> y[i] >> z[i];
  for (long long i = 1; i <= k; i++) cin >> b[i];
  for (long long i = 1; i <= m; i++) {
    for (long long j = 1; j <= k; j++) {
      if (b[j] <= y[i] && b[j] >= x[i]) ans += (z[i] + b[j] - x[i]);
    }
  }
  return cout << ans << "\n", 0;
}
