// Exported by Exporter.exe

// Included from TLE.cpp
// Uses MCMF, should TLE
// Only work when max(n, m) <= 1000
#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define F first
#define S second
#define MP make_pair
#define MTP make_tuple
#define R Read
#define RD Read_Digit
#define RP Read_P
#define RL Read_Loop
#define RLD Read_Loop_Digit
#define RLP Read_Loop_P
#define RS Read_String
#ifdef ONLINE_JUDGE
	#define Debug(...) ;
	#define Debug_Array(n,x) ;
	#define Debugln_Array(n,x) ;
	#define NL ;
#else
	#define Debug(...) {printf("(%s) = ",(#__VA_ARGS__)),_print(__VA_ARGS__),printf("\n");}
	#define Debug_Array(n,x) {printf("%s :",(#x));for(int i=1;i<=n;i++)printf(" "),_print(x[i]);printf("\n");}
	#define Debugln_Array(n,x) {for(int i=1;i<=n;i++){printf("%s",(#x));printf("[%d] = ", i);_print(x[i]);printf("\n");}}
	#define NL {printf("\n");}
#endif
typedef long long int ll;
typedef unsigned long long int ull;

constexpr int kN = int(5E3 + 10);
constexpr int kM = int(1E5 + 10);
// constexpr int kMod = 998244353;
// constexpr int kMod = int(1E9 + 7);
// constexpr int kInf = 0x3f3f3f3f;
// constexpr ll kInf = 0x3f3f3f3f3f3f3f3f;
// constexpr double kPi = acos(-1);
// constexpr double kEps = 1E-9;


// Included from C:\Users\ianli\Desktop\CP\template\Various\Fast_IO\Fast_IO.cpp
bool Fast_IO_activated = false;
bool IOS_activated = false;
// --- Get ---
static inline char Get_Raw_Char() {
	static bool pre = Fast_IO_activated = true;
	static char buf[1 << 16], *p = buf, *end = buf;
	if (p == end) {
		if ((end = buf + fread(buf, 1, 1 << 16, stdin)) == buf) return '\0';
		p = buf;
	}
	return *p++;
}

// --- Read ---
template <typename T> static inline void Read_P(T &n) {
	static_assert(is_integral<T>::value, "Read_P requires an integral type");
	char c;
	while (!isdigit(c = Get_Raw_Char())) ;
	n = int(c - '0');
	while (isdigit(c = Get_Raw_Char())) n = n * 10 + int(c - '0');
	return ;
}

template <typename T> static inline void Read(T &n) {
	static_assert(is_integral<T>::value, "Read requires an integral type");
	char c;
	bool neg = false;
	while (!isdigit(c = Get_Raw_Char())) if (c == '-') neg = true;
	n = int(c - '0');
	while (isdigit(c = Get_Raw_Char())) n = n * 10 + int(c - '0');
	if (neg) n = -n;
	return ;
}

template <typename T> static inline void Read_Digit(T &n) {
	static_assert(is_integral<T>::value, "Read_Digit requires an integral type");
	char c;
	while (!isdigit(c = Get_Raw_Char())) ;
	n = int(c - '0');
	return ;
}

static inline void Read_String(string &s) {
	char c = Get_Raw_Char();
	while (c == ' ' || c == '\n') c = Get_Raw_Char();
	while (c != ' ' && c != '\n') {
		s += c;
		c = Get_Raw_Char();
	}
	return ;
}

// --- Read multiple ---
template <typename T, typename... Targs> static inline void Read(T &n, Targs&... Fargs) {Read(n); return Read(Fargs...);}
template <typename T, typename... Targs> static inline void Read_Digit(T &n, Targs&... Fargs) {Read_Digit(n); return Read_Digit(Fargs...);}
template <typename T, typename... Targs> static inline void Read_P(T &n, Targs&... Fargs) {Read_P(n); return Read_P(Fargs...);}

// --- Read Loop ---
template <typename T> static inline void Read_Loop_i(int i, T *a) {return Read(a[i]);}
template <typename T, typename... Targs> static inline void Read_Loop_i(int i, T *a, Targs*... Fargs) {Read(a[i]); return Read_Loop_i(i, Fargs...);}
template <typename... Targs> static inline void Read_Loop(int n, Targs*... Fargs) {for (int i = 1; i <= n; i++) Read_Loop_i(i, Fargs...);}

template <typename T> static inline void Read_Loop_Digit_i(int i, T *a) {return Read_Digit(a[i]);}
template <typename T, typename... Targs> static inline void Read_Loop_Digit_i(int i, T *a, Targs*... Fargs) {Read_Digit(a[i]); return Read_Loop_Digit_i(i, Fargs...);}
template <typename... Targs> static inline void Read_Loop_Digit(int n, Targs*... Fargs) {for (int i = 1; i <= n; i++) Read_Loop_Digit_i(i, Fargs...);}

template <typename T> static inline void Read_Loop_P_i(int i, T *a) {return Read_P(a[i]);}
template <typename T, typename... Targs> static inline void Read_Loop_P_i(int i, T *a, Targs*... Fargs) {Read_P(a[i]); return Read_Loop_P_i(i, Fargs...);}
template <typename... Targs> static inline void Read_Loop_P(int n, Targs*... Fargs) {for (int i = 1; i <= n; i++) Read_Loop_P_i(i, Fargs...);}

// --- Float ---
template <int mul, typename T> static inline void Read(T &n) {
	char c;
	bool neg = false;
	while (!isdigit(c = Get_Raw_Char())) if (c == '-') neg = true;
	n = int(c - '0');
	while (isdigit(c = Get_Raw_Char())) n = n * 10 + int(c - '0');

	int cnt = 0;

	if (c == '.') {
		while (isdigit(c = Get_Raw_Char())) {
			n = n * 10 + int(c - '0');
			cnt++;
		}
	}

	while (cnt++ < mul) n = n * 10;

	if (neg) n = -n;
	return ;
}

template <int mul, typename T> static inline void Read_P(T &n) {
	char c;
	while (!isdigit(c = Get_Raw_Char())) ;

	n = int(c - '0');
	while (isdigit(c = Get_Raw_Char())) n = n * 10 + int(c - '0');

	int cnt = 0;

	if (c == '.') {
		while (isdigit(c = Get_Raw_Char())) {
			n = n * 10 + int(c - '0');
			cnt++;
		}
	}

	while (cnt++ < mul) n = n * 10;
	return ;
}

template <int mul, typename T, typename... Targs> static inline void Read(T &n, Targs&... Fargs) {Read<mul>(n); return Read<mul>(Fargs...);}
template <int mul, typename T, typename... Targs> static inline void Read_P(T &n, Targs&... Fargs) {Read_P<mul>(n); return Read_P<mul>(Fargs...);}

// --- init ---
inline void IOS() {
	IOS_activated = true;
	ios::sync_with_stdio(false); cin.tie(0);
}
inline void Freopen(const char *in, const char *out) {freopen(in, "r", stdin); freopen(out, "w", stdout); return ;}

// --- Output ---
template <typename T> void Print(T x) {
	if (x < 0) {
		printf("-");
		x = -x;
	}
	if (x == 0) printf("0");
	else {
		static int val[100];
		int idx = -1;
		while (x) {
			val[++idx] = x % 10;
			x /= 10;
		}
		while (idx >= 0) printf("%d", val[idx--]);
	}
} 
// End of C:\Users\ianli\Desktop\CP\template\Various\Fast_IO\Fast_IO.cpp

// Included from C:\Users\ianli\Desktop\CP\template\Various\Useful_Functions\Useful_Functions.cpp
template <typename T> inline void sort(vector<T> &v) {return sort(v.begin(), v.end());}
template <typename T> inline void sort_r(vector<T> &v) {return sort(v.begin(), v.end(), greater<T>());}
inline void sort(string &s) {return sort(s.begin(), s.end());}
inline void sort_r(string &s) {return sort(s.begin(), s.end(), greater<char>());}

template <typename T> inline void reverse(vector<T> &v) {return reverse(v.begin(), v.end());}
inline void reverse(string &s) {return reverse(s.begin(), s.end());}

template <typename T> inline void Merge(vector<T> &a, vector<T> &b, vector<T> &c) {
	if (c.size() < a.size() + b.size()) c.resize(a.size() + b.size());
	merge(a.begin(), a.end(), b.begin(), b.end(), c.begin());
	return ;
}
template <typename T> inline void Concatanate(vector<T> &a, vector<T> &b, vector<T> &c) {
	int a_size = int(a.size()), b_size = int(b.size());
	c.resize(a_size + b_size);
	for (int i = 0; i < a_size; i++) c[i] = a[i];
	for (int i = 0; i < b_size; i++) c[i + a_size] = b[i];
	return ;
}

template <typename T> inline void Discrete(vector<T> &v) {sort(v); v.resize(unique(v.begin(), v.end()) - v.begin()); return ;}

template <typename T> using PQ = priority_queue<T>;
template <typename T> using PQ_R = priority_queue<T, vector<T>, greater<T>>;

template <typename T> inline T ABS(T n) {return n >= 0 ? n : -n;}
template <typename T> __attribute__((target("bmi"))) inline T gcd(T a, T b) {
	if (a < 0) a = -a;
	if (b < 0) b = -b;
	if (a == 0 || b == 0) return a + b;
	int n = __builtin_ctzll(a);
	int m = __builtin_ctzll(b);
	a >>= n;
	b >>= m;
	while (a != b) {
		int m = __builtin_ctzll(a - b);
		bool f = a > b;
		T c = f ? a : b;
		b = f ? b : a;
		a = (c - b) >> m;
	}
	return a << min(n, m);
}
template <typename T> inline T lcm(T a, T b) {return a * (b / gcd(a, b));}
template <typename T, typename... Targs> inline T gcd(T a, T b, T c, Targs... args) {return gcd(a, gcd(b, c, args...));}
template <typename T, typename... Targs> inline T lcm(T a, T b, T c, Targs... args) {return lcm(a, lcm(b, c, args...));}
template <typename T, typename... Targs> inline T min(T a, T b, T c, Targs... args) {return min(a, min(b, c, args...));}
template <typename T, typename... Targs> inline T max(T a, T b, T c, Targs... args) {return max(a, max(b, c, args...));}
template <typename T, typename... Targs> inline void chmin(T &a, T b, Targs... args) {a = min(a, b, args...); return ;}
template <typename T, typename... Targs> inline void chmax(T &a, T b, Targs... args) {a = max(a, b, args...); return ;}

vector<int> Primes(int n) {
	if (n == 1) return {};
	// 2 ~ n
	vector<int> primes;
	vector<bool> isPrime(n + 1, true);

	primes.reserve(n / __lg(n));

	for (int i = 2; i <= n; i++) {
		if (isPrime[i]) primes.push_back(i);
		for (int j : primes) {
			if (i * j > n) break;
			isPrime[i * j] = false;
			if (i % j == 0) break;
		}
	}
	return primes;
}

template <typename T> vector<T> factors(T x) {
	// maybe use factorize would be faster?
	vector<T> ans;
	for (T i = 1; i * i <= x; i++) if (x % i == 0) ans.push_back(i);

	int id = int(ans.size()) - 1;
	if (ans[id] * ans[id] == x) id--;
	for (int i = id; i >= 0; i--) ans.push_back(x / ans[i]);

	return ans;
}

int mex(vector<int> vec) {
	int n = int(vec.size());
	vector<bool> have(n, false);
	for (int i : vec) if (i < n) have[i] = true;
	for (int i = 0; i < n; i++) if (!have[i]) return i;
	return n;
}

template <typename T> T SQ(T x) {return x * x;}

template <typename T> T Mdist(pair<T, T> lhs, pair<T, T> rhs) {return ABS(lhs.first - rhs.first) + ABS(lhs.second - rhs.second);}
template <typename T> T Dist2(pair<T, T> lhs, pair<T, T> rhs) {
	return SQ(lhs.F - rhs.F) + SQ(lhs.S - rhs.S);
}

template <typename T> T LUBound(T LB, T val, T UB) {return min(max(LB, val), UB);}

template <typename T, typename Comp> T Binary_Search(T L, T R, Comp f) {
	// L good R bad
	static_assert(is_integral<T>::value, "Binary_Search requires an integral type");
	while (R - L > 1) {
		T mid = (L + R) >> 1;
		if (f(mid)) L = mid;
		else R = mid;
	}
	return L;
}

template <typename Comp> double Binary_Search(double L, double R, Comp f, int n = 30) {
	for (int i = 1; i <= n; i++) {
		double mid = (L + R) / 2;
		if (f(mid)) L = mid;
		else R = mid;
	}
	return L;
}

template <typename T> T nearest(set<T> &se, T val) {
	static constexpr T kInf = numeric_limits<T>::max() / 2 - 10;

	if (se.empty()) return kInf;
	else if (val <= *se.begin()) return *se.begin() - val;
	else if (val >= *prev(se.end())) return val - *prev(se.end());
	else {
		auto u = se.lower_bound(val);
		auto v = prev(u);
		return min(*u - val, val - *v);
	}
}

namespace MR32 {
	using ull = unsigned long long int;
	using uint = unsigned int;
	ull PowMod(ull a, ull b, ull kMod) {
		ull ans = 1;
		for (; b; b >>= 1, a = a * a % kMod) if (b & 1) ans = ans * a % kMod;
		return ans;
	}

	bool IsPrime(uint x) {
		static constexpr bool low[8] = {false, false, true, true, false, true, false, true};
		static constexpr uint as = 3, a[3] = {2, 7, 61};
		if (x < 8) return low[x];

		uint t = x - 1;
		int r = 0;
		while ((t & 1) == 0) {
			t >>= 1;
			r++;
		}
		for (uint i = 0; i < as; i++) if (a[i] <= x - 2) {
			bool ok = false;
			ull tt = PowMod(a[i], t, x);
			if (tt == 1) continue;
			for (int j = 0; j < r; j++, tt = tt * tt % x) if (tt == x - 1) {
				ok = true;
				break;
			}
			if (!ok) return false;
		}
		return true;
	}
}

#ifdef __SIZEOF_INT128__
namespace MR64 {
	using uint128 = unsigned __int128;
	using ull = unsigned long long int;
	using uint = unsigned int;
	uint128 PowMod(uint128 a, uint128 b, uint128 kMod) {
		uint128 ans = 1;
		for (; b; b >>= 1, a = a * a % kMod) if (b & 1) ans = ans * a % kMod;
		return ans;
	}

	bool IsPrime(ull x) {
		static constexpr bool low[8] = {false, false, true, true, false, true, false, true};
		static constexpr uint as = 7, a[7] = {2, 325, 9375, 28178, 450775, 9780504, 1795265022};
		if (x < 8) return low[x];
		ull t = x - 1;
		int r = 0;
		while ((t & 1) == 0) {
			t >>= 1;
			r++;
		}
		for (uint i = 0; i < as; i++) if (a[i] <= x - 2) {
			bool ok = false;
			uint128 tt = PowMod(a[i], t, x);
			if (tt == 1) continue;
			for (int j = 0; j < r; j++, tt = tt * tt % x) if (tt == x - 1) {
				ok = true;
				break;
			}
			if (!ok) return false;
		}
		return true;
	}
}
#endif

bool IsPrime(unsigned long long int x) {
#ifdef __SIZEOF_INT128__
	if ((x >> 32) == 0) return MR32::IsPrime(x);
	else return MR64::IsPrime(x);
#endif
	return MR32::IsPrime(x);
}

#ifdef __SIZEOF_INT128__
uint64_t PollardRho(uint64_t x) {
	static mt19937 rng;
	if (!(x & 1)) return 2;
	if (IsPrime(x)) return x;
  int64_t a = rng() % (x - 2) + 2, b = a;
  uint64_t c = rng() % (x - 1) + 1, d = 1;
  while (d == 1) {
    a = (__int128(a) * a + c) % x;
    b = (__int128(b) * b + c) % x;
    b = (__int128(b) * b + c) % x;
    d = __gcd(uint64_t(abs(a - b)), x);
    if (d == x) return PollardRho(x);
  }
  return d;
}
#endif

template <typename T> vector<T> factorize(T x) {
	if (x <= 1) return {};
	T p = PollardRho(x);
	if (p == x) return {x};
	vector<T> ans, lhs = factorize(p), rhs = factorize(x / p);
	Merge(lhs, rhs, ans);
	return ans;
}

template <typename T> vector<pair<T, int>> Compress(vector<T> vec) {
	// vec must me sorted
	if (vec.empty()) return {};

	vector<pair<T, int>> ans;
	int cnt = 1, sz = int(vec.size());
	T lst = vec[0];
	for (int i = 1; i < sz; i++) {
		if (lst != vec[i]) {
			ans.push_back(make_pair(lst, cnt));
			lst = vec[i];
			cnt = 1;
		}
		else cnt++;
	}
	ans.push_back(make_pair(lst, cnt));
	return ans;
}
// End of C:\Users\ianli\Desktop\CP\template\Various\Useful_Functions\Useful_Functions.cpp

// Included from C:\Users\ianli\Desktop\CP\template\Various\Debug\Debug.cpp
template <typename T> void _print(vector<T> v) ;
void _print(bool x) {printf("%d", x ? 1 : 0);}
void _print(char x) {printf("%c", x);}
void _print(short x) {printf("%hd", x);}
void _print(unsigned short x) {printf("%hu", x);}
void _print(int x) {printf("%d", x);}
void _print(unsigned int x) {printf("%u", x);}
void _print(long long int x) {printf("%lld", x);}
void _print(unsigned long long int x) {printf("%llu", x);}
void _print(float x) {printf("%f", x);}
void _print(double x) {printf("%lf", x);}
void _print(long double x) {printf("%Lf", x);}
#ifdef __SIZEOF_INT128__
void _print(__int128 x) {
	if (x < 0) {
		printf("-");
		x = -x;
	}
	if (x == 0) printf("0");
	else {
		static int val[100];
		int idx = -1;
		while (x) {
			val[++idx] = x % 10;
			x /= 10;
		}
		while (idx >= 0) printf("%d", val[idx--]);
	}
}
void _print(unsigned __int128 x) {
	if (x < 0) {
		printf("-");
		x = -x;
	}
	if (x == 0) printf("0");
	else {
		static int val[100];
		int idx = -1;
		while (x) {
			val[++idx] = x % 10;
			x /= 10;
		}
		while (idx >= 0) printf("%d", val[idx--]);
	}
}
#endif
template <typename T1, typename T2> void _print(pair<T1, T2> x) {printf("("); _print(x.first); printf(", "); _print(x.second); printf(")");}
template <typename T1, typename T2, typename T3> void _print(tuple<T1, T2, T3> x) {printf("("); _print(get<0>(x)); printf(", "); _print(get<1>(x)); printf(", "); _print(get<2>(x)); printf(")");}
template <typename T> void _print(vector<T> v) {
	if (v.empty()) printf(" empty");
	else {
		bool first = true;
		for (T i : v) {
			if (first) first = false;
			else printf(", ");
			_print(i);
		}
	}
}
template <typename T> void _print(set<T> s) {
	if (s.empty()) printf(" empty");
	else {
		bool first = true;
		for (T i : s) {
			if (first) first = false;
			else printf(", ");
			_print(i);
		}
	}
}
template <typename T> void _print(stack<T> s) {
	if (s.empty()) printf(" empty");
	else {
		_print(s.top()); s.pop();
		while (!s.empty()) {printf(", "); _print(s.top()); s.pop();}
	}
}
template <typename T> void _print(queue<T> q) {
	if (q.empty()) printf(" empty");
	else {
		_print(q.front()); q.pop();
		while (!q.empty()) {printf(", "); _print(q.front()); q.pop();}
	}
}
template <typename T> void _print(deque<T> dq) {
	if (dq.empty()) printf(" empty");
	else {
		_print(dq.front()); dq.pop_front();
		while (!dq.empty()) {printf(", "); _print(dq.front()); dq.pop_front();}
	}
}
template <typename T1, typename T2, typename T3> void _print(priority_queue<T1, T2, T3> pq) {
	if (pq.empty()) printf(" empty");
	else {
		_print(pq.top()); pq.pop();
		while (!pq.empty()) {printf(", "); _print(pq.top()); pq.pop();}
	}
}
template <int size> void _print(bitset<size> bs) {
	for (int i = 0; i < size; i++) printf("%d", bs[i] ? 1 : 0);
}
template <typename T1, typename T2> void _print(map<T1, T2> m) {
	if (m.empty()) printf(" empty");
	else {
		bool first = true;
		for (pair<T1, T2> i : m) {
			if (first) first = false;
			else printf(", ");
			_print(i);
		}
	}
}

template <typename T> void _print(T x) {return x.out();}
template <typename T, typename... Targs> void _print(T x, Targs... Fargs) {_print(x); printf(", "); _print(Fargs...);}
// End of C:\Users\ianli\Desktop\CP\template\Various\Debug\Debug.cpp

// Included from C:\Users\ianli\Desktop\CP\template\Flow\MCMF\MCMF.cpp
// AddEdge(u, v, cap, cost)
template <typename T> struct MCMF {
	struct Edge {
		int to, rev;
		T cap, wei;
		Edge (int a, T b, T c, int d) {to = a; cap = b; wei = c; rev = d;}
	};

	vector<vector<Edge>> graph;
	vector<T> d;
	vector<int> p, ed;
	vector<bool> inq;
	int size;
	static constexpr T kInf = numeric_limits<T>::max() / 2 - 10;

	void init(int n) {
		size = n;
		graph.clear(); graph.resize(n);
		d.clear(); d.resize(n);
		p.clear(); p.resize(n);
		ed.clear(); ed.resize(n);
		inq.clear(); inq.resize(n);
		return ;
	}

	void AddEdge(int a, int b, T c, T d) {
		graph[a].push_back(Edge(b, c, d, int(graph[b].size())));
		graph[b].push_back(Edge(a, 0, -d, int(graph[a].size()) - 1));
		return ;
	}

	bool spfa(int s, int t, T &f, T &c) {
		for (int i = 0; i < size; i++) {
			d[i] = kInf;
			p[i] = ed[i] = -1;
			inq[i] = false;
		}

		d[s] = 0;
		queue<int> q;
		q.push(s);
		while (!q.empty()) {
			int x = q.front(); q.pop();
			inq[x] = false;
			for (int i = 0; i < int(graph[x].size()); i++) {
				Edge &e = graph[x][i];
				if (e.cap > 0 && d[e.to] > d[x] + e.wei) {
					d[e.to] = d[x] + e.wei;
					p[e.to] = x;
					ed[e.to] = i;
					if (!inq[e.to]) {
						q.push(e.to);
						inq[e.to] = true;
					}
				}
			}
		}

		if (d[t] == kInf) return false;

		T dlt = kInf;
		for (int x = t; x != s; x = p[x]) dlt = min(dlt, graph[p[x]][ed[x]].cap);
		for (int x = t; x != s; x = p[x]) {
			Edge &e = graph[p[x]][ed[x]];
			e.cap -= dlt;
			graph[e.to][e.rev].cap += dlt;
		}

		f += dlt; c += d[t] * dlt;
		return true;
	}

	pair<T, T> operator () (int s, int t) {
		T f = 0, c = 0;
		while (spfa(s, t, f, c));
		return make_pair(f, c);
	}
};
// End of C:\Users\ianli\Desktop\CP\template\Flow\MCMF\MCMF.cpp

MCMF<ll> mcmf;
int x[kM], y[kM], z[kM];
int nid[kN], mid[kN];

int main() {
	int n, m, k, l; RP(n, m, k, l);
	RLP(l, x, y, z);

	if (max(n, m) <= 1000) {
		int cnt = 0;
		for (int i = 1; i <= n; i++) nid[i] = cnt++;
		for (int i = 1; i <= m; i++) mid[i] = cnt++;
		int S = cnt++;
		int T = cnt++;

		mcmf.init(cnt);

		for (int i = 1; i <= n; i++) mcmf.AddEdge(S, nid[i], 1, 0);
		for (int i = 1; i <= m; i++) mcmf.AddEdge(mid[i], T, 1, 0);
		for (int i = 1; i <= l; i++) mcmf.AddEdge(nid[x[i]], mid[y[i]], 1, (1 << 30) - (1 << z[i]));
		for (int i = 1; i <= n; i++) mcmf.AddEdge(nid[i], T, 1, (1 << 30));

		printf("%lld\n", (ll(n) << 30) - mcmf(S, T).S);
	}
}
// End of TLE.cpp