#define LOCAL
#define _USE_MATH_DEFINES
#include <array>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>
#include <random>
#include <ctime>

using namespace std;

template <typename A, typename B>
ostream& operator <<(ostream& out, const pair<A, B>& a) {
  out << "(" << a.first << "," << a.second << ")";
  return out;
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
#ifdef LOCAL
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
#else
#define trace(...) 42
#endif
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

typedef long long int64;
typedef pair<int, int> ii;
#define SZ(x) (int)((x).size())
const int INF = 1 << 29;
const int MOD = 1e9 + 7;
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }

struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  };
} fast_ios_;

int main() {
  int n, m, cntA, cntB;
  cin >> n >> m >> cntA >> cntB;
  vector<vector<int>> a(n, vector<int>(m));
  vector<vector<int>> dp(n, vector<int>(m));
  for (int i = 0; i < cntA; ++i) {
    int x, y;
    cin >> x >> y;
    --x; --y;
    a[x][y] = 1;
  }
  vector<vector<bool>> b(n, vector<bool>(m));
  for (int i = 0; i < cntB; ++i) {
    int x, y;
    cin >> x >> y;
    --x; --y;
    b[x][y] = true;
  }
  for (int i = 0; i < n; ++i) {
    int cur = 0;
    for (int j = 0; j < m; ++j) {
      if (b[i][j]) {
        cur = 0;
      } else {
        cur += a[i][j];
        dp[i][j] += cur;
      }
    }
    cur = 0;
    for (int j = m - 1; j >= 0; --j) {
      if (b[i][j]) {
        cur = 0;
      } else {
        cur += a[i][j];
        dp[i][j] += cur;
      }
    }
  }
  for (int j = 0; j < m; ++j) {
    int cur = 0;
    for (int i = 0; i < n; ++i) {
      if (b[i][j]) {
        cur = 0;
      } else {
        cur += a[i][j];
        dp[i][j] += cur;
      }
    }
    cur = 0;
    for (int i = n - 1; i >= 0; --i) {
      if (b[i][j]) {
        cur = 0;
      } else {
        cur += a[i][j];
        dp[i][j] += cur;
      }
    }
  }
  int ret = 0;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      if (b[i][j]) continue;
      ret += dp[i][j] > 0;
    }
  }
  cout << ret << '\n';
  return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n; long long C;
	cin >> n >> C;

	vector<int> a(n), b(n), c(n);
	for (int i = 0; i < n; i++) cin >> a[i] >> b[i] >> c[i];

	map<int, vector<int>> mp;
	for (int i = 0; i < n; i++) {
		mp[a[i]].push_back(c[i]);
		mp[b[i] + 1].push_back(-c[i]);
	}

	int last = 0;
	long long ans = 0, cur_cost = 0;

	for (auto &[k, v] : mp) {
		ans += min(C, cur_cost) * (k - last);
		for (auto &x : v) {
			cur_cost += x;
		}
		last = k;
	}
	cout << ans << '\n';
	return 0;
}