import java.util.*;
import java.io.*;

public class PriorityQueueP {
	//https://pastebin.com/Nhe9rTN5
	public static class Edge implements Comparable<Edge>{
		int s, d;long  wt; boolean v;
		public Edge(int s, int d, int wt, boolean v)
		{this.s = s; this.d = d; this.wt = wt; this.v = v;}
		@Override
		public int compareTo(Edge o) {
			return Long.compare(this.wt, o.wt);
		}
	}

	public static class DisjointSet{
		int par[], N;
		public DisjointSet(int N) {
			this.N= N;
			par = new int[N+1];
			for(int i = 1; i<=N; i++)
				par[i] = i;
		}

		public int find(int x)
		{
			if(par[x] == x)  {
				return x;
			}
			return par[x] = find(par[x]);
		}

		public void union(int x, int y) {
			par[x] = y;
		}
	}

	public static void main(String[] args) throws IOException {
		//N is planet
		//M is city
		int N = readInt(), M = readInt(), P = readInt(), Q = readInt(); long total = 0, MST = 0;
		PriorityQueue<Edge> pq = new PriorityQueue<Edge>();
		for(int i = 1; i<=P; i++)
			pq.add(new Edge(readInt(), readInt(), readInt(), false));
		for(int i = 1; i<=Q; i++)
			pq.add(new Edge(readInt(), readInt(), readInt(), true));
		DisjointSet Ns = new DisjointSet(N), Ms = new DisjointSet(M);

		while(!pq.isEmpty()) {
			Edge e = pq.poll();
			if(!e.v) {
				total += e.wt*N;
				if(Ms.N != 0 && Ms.find(e.d) != Ms.find(e.s)) {
					MST += Ns.N*e.wt;
					Ms.union(Ms.find(e.d), Ms.find(e.s));
					Ms.N -= 1;
				}
			}
			else {
				total += e.wt*M;
				if(Ns.N != 0 && Ns.find(e.d) != Ns.find(e.s)) {
					MST += Ms.N*e.wt;
					Ns.union(Ns.find(e.d), Ns.find(e.s));
					Ns.N -= 1;
				}
			}
		}
		println(total-MST);
		exit();
	}

	final private static int BUFFER_SIZE = 1 << 16;
	private static DataInputStream din = new DataInputStream(System.in);
	private static byte[] buffer = new byte[BUFFER_SIZE];
	private static int bufferPointer = 0, bytesRead = 0;
	static PrintWriter pr = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

	public static String readLine() throws IOException {
		byte[] buf = new byte[64]; // line length
		int cnt = 0, c;
		while ((c = Read()) != -1) {
			if (c == '\n')
				break;
			buf[cnt++] = (byte) c;
		}
		return new String(buf, 0, cnt);
	}

	public static String read() throws IOException {
		byte[] ret = new byte[1024];
		int idx = 0;
		byte c = Read();
		while (c <= ' ') {
			c = Read();
		}
		do {
			ret[idx++] = c;
			c = Read();
		} while (c != -1 && c != ' ' && c != '\n' && c != '\r');
		return new String(ret, 0, idx);
	}

	public static int readInt() throws IOException {
		int ret = 0;
		byte c = Read();
		while (c <= ' ')
			c = Read();
		boolean neg = (c == '-');
		if (neg)
			c = Read();
		do {
			ret = ret * 10 + c - '0';
		} while ((c = Read()) >= '0' && c <= '9');

		if (neg)
			return -ret;
		return ret;
	}

	public static long readLong() throws IOException {
		long ret = 0;
		byte c = Read();
		while (c <= ' ')
			c = Read();
		boolean neg = (c == '-');
		if (neg)
			c = Read();
		do {
			ret = ret * 10 + c - '0';
		} while ((c = Read()) >= '0' && c <= '9');
		if (neg)
			return -ret;
		return ret;
	}

	public static double readDouble() throws IOException {
		double ret = 0, div = 1;
		byte c = Read();
		while (c <= ' ')
			c = Read();
		boolean neg = (c == '-');
		if (neg)
			c = Read();

		do {
			ret = ret * 10 + c - '0';
		} while ((c = Read()) >= '0' && c <= '9');

		if (c == '.') {
			while ((c = Read()) >= '0' && c <= '9') {
				ret += (c - '0') / (div *= 10);
			}
		}

		if (neg)
			return -ret;
		return ret;
	}

	private static void fillBuffer() throws IOException {
		bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
		if (bytesRead == -1)
			buffer[0] = -1;
	}

	private static byte Read() throws IOException {
		if (bufferPointer == bytesRead)
			fillBuffer();
		return buffer[bufferPointer++];
	}

	public void close() throws IOException {
		if (din == null)
			return;
		din.close();
	}

	static void print(Object o) {
		pr.print(o);
	}

	static void println(Object o) {
		pr.println(o);
	}

	static void flush() {
		pr.flush();
	}

	static void println() {
		pr.println();
	}

	static void exit() throws IOException {
		din.close();
		pr.close();
		System.exit(0);
	}
}