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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int d = sc.nextInt();
        int w = sc.nextInt();
        UnionFindTree drive = new UnionFindTree(n);
        for (int i = 0; i < d; i++) {
            drive.unite(sc.nextInt() - 1, sc.nextInt() - 1);
        }
        UnionFindTree walk = new UnionFindTree(n);
        for (int i = 0; i < w; i++) {
            walk.unite(sc.nextInt() - 1, sc.nextInt() - 1);
        }
        HashMap<Integer, Integer> counts = new HashMap<>();
        long ans = 0;
        for (int i = 0; i < n; i++) {
            int x = drive.find(i);
            if (counts.containsKey(x)) {
                ans += counts.get(x);
                continue;
            }
            HashSet<Integer> current = drive.getSet(x);
            HashSet<Integer> against = new HashSet<>();
            HashSet<Integer> exist = new HashSet<>();
            for (int y : current) {
                int z = walk.find(y);
                if (exist.contains(z)) {
                    continue;
                }
                exist.add(z);
                against.addAll(walk.getSet(z));
            }
            current.addAll(against);
            counts.put(x, current.size() - 1);
            ans += current.size() - 1;
        }
        System.out.println(ans);
    }
    
    static class UnionFindTree {
        int[] parents;
        ArrayList<HashSet<Integer>> groups = new ArrayList<>();
        
        public UnionFindTree(int size) {
            parents = new int[size];
            for (int i = 0; i < size; i++) {
                parents[i] = i;
                groups.add(new HashSet<>());
                groups.get(i).add(i);
            }
        }
        
        public int find(int x) {
            if (x == parents[x]) {
                return x;
            } else {
                return parents[x] = find(parents[x]);
            }
        }
        
        public boolean same(int x, int y) {
            return find(x) == find(y);
        }
        
        public void unite(int x, int y) {
            int xx = find(x);
            int yy = find(y);
            if (xx == yy) {
                return;
            }
            if (groups.get(xx).size() < groups.get(yy).size()) {
                parents[xx] = yy;
                groups.get(yy).addAll(groups.get(xx));
            } else {
                parents[yy] = xx;
                groups.get(xx).addAll(groups.get(yy));
            }
        }
        
        public HashSet<Integer> getSet(int x) {
            return groups.get(find(x));
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}