description: This is the easy version of the problem. The only difference between the two versions is the constraint on n. You can make hacks only if all versions of the problem are solved.
  
  A forest is an undirected graph without cycles (not necessarily connected).
  
  Mocha and Diana are friends in Zhijiang, both of them have a forest with nodes numbered from 1 to n, and they would like to add edges to their forests such that: 
  
    * After adding edges, both of their graphs are still forests. 
    * They add the same edges. That is, if an edge (u, v) is added to Mocha's forest, then an edge (u, v) is added to Diana's forest, and vice versa. 
  
  
  
  Mocha and Diana want to know the maximum number of edges they can add, and which edges to add.
  
  Input
  
  The first line contains three integers n, m_1 and m_2 (1 ≤ n ≤ 1000, 0 ≤ m_1, m_2 < n) — the number of nodes and the number of initial edges in Mocha's forest and Diana's forest.
  
  Each of the next m_1 lines contains two integers u and v (1 ≤ u, v ≤ n, u ≠ v) — the edges in Mocha's forest.
  
  Each of the next m_2 lines contains two integers u and v (1 ≤ u, v ≤ n, u ≠ v) — the edges in Diana's forest.
  
  Output
  
  The first line contains only one integer h, the maximum number of edges Mocha and Diana can add (in each forest).
  
  Each of the next h lines contains two integers u and v (1 ≤ u, v ≤ n, u ≠ v) — the edge you add each time.
  
  If there are multiple correct answers, you can print any one of them.
  
  Examples
  
  Input
  
  
  3 2 2
  1 2
  2 3
  1 2
  1 3
  
  
  Output
  
  
  0
  
  
  Input
  
  
  5 3 2
  5 4
  2 1
  4 3
  4 3
  1 4
  
  
  Output
  
  
  1
  2 4
  
  
  Input
  
  
  8 1 2
  1 7
  2 6
  1 5
  
  
  Output
  
  
  5
  5 2
  2 3
  3 4
  4 7
  6 8
  
  Note
  
  In the first example, we cannot add any edge.
  
  In the second example, the initial forests are as follows.
  
  <image>
  
  We can add an edge (2, 4).
  
  <image>
solution: import java.io.*;
  import java.util.*;
  
  public class Main {
  	static InputReader in = new InputReader(System.in);
  	static OutputWriter out = new OutputWriter(System.out);
  
  	public static void main(String[] args) throws IOException {
  		int t = 1;
  //		t = i();
  		sb = new StringBuilder();
  		while (t-- > 0) {
  			solve();
  		}
  		out.println(sb.toString());
  		out.close();
  
  	}
  
  	static int mod = 1000000007;
  	static StringBuilder sb;
  
  	private static void solve() {
  		int n = i();
  		int m1 = i();
  		int m2 = i();
  		int[][] g1 = new int[n + 1][n + 1];
  		int[][] g2 = new int[n + 1][n + 1];
  
  		dsu d1 = new dsu(n + 1);
  		dsu d2 = new dsu(n + 1);
  
  		for (int i = 0; i < m1; i++) {
  			int u = i();
  			int v = i();
  			g1[u][v] = 1;
  			d1.union(u, v);
  		}
  		for (int i = 0; i < m2; i++) {
  			int u = i();
  			int v = i();
  			g2[u][v] = 1;
  			d2.union(u, v);
  		}
  
  		int count = 0;
  		StringBuilder sb1 = new StringBuilder();
  
  		for (int i = 1; i <= n; i++) {
  			for (int j = i + 1; j <= n; j++) {
  				if (g1[i][j] == 0 && g2[i][j] == 0 && d1.find(i)!=d1.find(j) && d2.find(i)!=d2.find(j)) {
  					count++;
  					d1.union(i, j);
  					d2.union(i, j);
  					sb1.append(i + " ");
  					sb1.append(j + "\n");
  				}
  			}
  		}
  		sb.append(count + "\n");
  		if (count > 0) {
  			sb.append(sb1.toString());
  		}
  	}
  
  	static class Edge implements Comparable<Edge> {
  		int u;
  		int v;
  		int wt;
  
  		Edge(int u, int v, int wt) {
  			this.u = u;
  			this.v = v;
  			this.wt = wt;
  		}
  
  		public int compareTo(Edge o) {
  			return this.wt - o.wt;
  		}
  	}
  
  // Fenwick Tree
  	static class fenwickTree {
  		int n;
  		long[] farr;
  
  		fenwickTree(int n, long[] a) {
  			this.n = n;
  			farr = new long[n + 1];
  			for (int i = 0; i < n; i++) {
  				update(i + 1, a[i]);
  			}
  		}
  
  		void update(int i, long val) {
  			while (i < farr.length) {
  				farr[i] += val;
  				i += (i & -i);
  			}
  		}
  
  		long sum(int i) {
  			long sum = 0L;
  			while (i > 0) {
  				sum += farr[i];
  				i -= (i & -i);
  			}
  			return sum;
  		}
  	}
  
  // *************Disjoint set
  // union*********//
  	static class dsu {
  		int[] par;
  		int[] rank;
  
  		dsu(int n) {
  			par = new int[n + 1];
  			rank = new int[n + 1];
  			for (int i = 0; i <= n; i++) {
  				par[i] = i;
  				rank[i] = 1;
  			}
  		}
  
  		int find(int a) {
  			if (par[a] == a) {
  				return a;
  			}
  			int x = find(par[a]);
  			par[a] = x;
  			return x;
  		}
  
  		boolean union(int a, int b) {
  			int pa = find(a);
  			int pb = find(b);
  			if (pa == pb) {
  				return false;
  			}
  			if (rank[pa] > rank[pb]) {
  				par[pb] = pa;
  			} else if (rank[pb] > rank[pa]) {
  				par[pa] = pb;
  			} else {
  				par[pa] = pb;
  				rank[pb]++;
  			}
  			return true;
  		}
  
  	}
  
  	// **************NCR%P******************
  	static long ncr(int n, int r) {
  		if (r > n)
  			return (long) 0;
  		long[] fact = new long[(int) 1e6 + 10];
  		fact[0] = fact[1] = 1;
  		for (int i = 2; i < fact.length; i++) {
  			fact[i] = ((long) (i % mod) * (long) (fact[i - 1] % mod)) % mod;
  		}
  		long res = fact[n] % mod;
  		res = ((long) (res % mod) * (long) (p(fact[r], mod - 2) % mod)) % mod;
  		res = ((long) (res % mod) * (long) (p(fact[n - r], mod - 2) % mod)) % mod;
  		return res;
  	}
  
  	static ArrayList<Integer> divisors(int n) {
  		ArrayList<Integer> al = new ArrayList<>();
  		for (int i = 1; i * i <= n; i++) {
  			if (n % i == 0) {
  				if (n == i * i) {
  					al.add(i);
  				} else {
  					al.add(i);
  					al.add(n / i);
  				}
  			}
  		}
  		Collections.sort(al);
  		return al;
  	}
  
  	static long p(long x, long y)// POWER FXN //
  	{
  		if (y == 0)
  			return 1;
  
  		long res = 1;
  		while (y > 0) {
  			if (y % 2 == 1) {
  				res = (res * x) % mod;
  				y--;
  			}
  
  			x = (x * x) % mod;
  			y = y / 2;
  
  		}
  		return res;
  	}
  
  	private static boolean pow2(int i) {
  		return (i & (i - 1)) == 0;
  	}
  
  	private static void sort(int[] arr) {
  		int n = arr.length;
  		ArrayList<Integer> res = new ArrayList<>();
  		for (int a : arr) {
  			res.add(a);
  		}
  		Collections.sort(res);
  		for (int i = 0; i < n; i++) {
  			arr[i] = res.get(i);
  		}
  	}
  
  	private static void sort(long[] arr) {
  		int n = arr.length;
  		ArrayList<Long> res = new ArrayList<>();
  		for (long a : arr) {
  			res.add(a);
  		}
  		Collections.sort(res);
  		for (int i = 0; i < n; i++) {
  			arr[i] = res.get(i);
  		}
  	}
  
  	private static void revSort(int[] arr) {
  		int n = arr.length;
  		ArrayList<Integer> res = new ArrayList<>();
  		for (int a : arr) {
  			res.add(a);
  		}
  		Collections.sort(res, Collections.reverseOrder());
  		for (int i = 0; i < n; i++) {
  			arr[i] = res.get(i);
  		}
  	}
  
  	private static ArrayList<Integer> sieveOfEratosthenes(int n) {
  		boolean[] arr = new boolean[n + 1];
  
  		arr[0] = arr[1] = true;
  		for (int i = 2; i * i <= n; i++) {
  			if (!arr[i]) {
  				for (int j = i * i; j <= n; j += i) {
  					arr[j] = true;
  				}
  			}
  		}
  		ArrayList<Integer> primes = new ArrayList<>();
  		for (int i = 2; i <= n; i++) {
  			if (!arr[i]) {
  				primes.add(i);
  			}
  		}
  		return primes;
  	}
  
  	private static ArrayList<Integer> segmentedSieve(int s, int e) {
  		int len = (int) (Math.sqrt(e) + 1);
  		ArrayList<Integer> primes = sieveOfEratosthenes(len);
  		boolean[] arr2 = new boolean[e - s + 1];
  		if (s == 1) {
  			arr2[0] = true;
  		}
  		ArrayList<Integer> res = new ArrayList<>();
  		for (int p : primes) {
  
  			int st = (int) (p * (Math.ceil((double) s / p)));
  			if (st < s) {
  				st += p;
  			}
  			if (st == p) {
  				st += p;
  			}
  			for (int i = st; i <= e; i += p) {
  				arr2[i - s] = true;
  			}
  		}
  		for (int i = 0; i < arr2.length; i++) {
  			if (!arr2[i]) {
  				res.add(i + s);
  			}
  		}
  		return res;
  	}
  
  	private static long pow(int n, int k) {
  		long res = 1;
  		long num = (long) n;
  		while (k > 0) {
  			if ((k & 1) == 1) {
  				res = (res * num) % mod;
  			}
  			k /= 2;
  			num = num * num % mod;
  		}
  		return res;
  	}
  
  	private static int countDigits(int n) {
  		int c = 0;
  		while (n != 0) {
  			c++;
  			n /= 10;
  		}
  		return c;
  	}
  
  	private static boolean palindrome(String str) {
  		int s = 0;
  		int e = str.length() - 1;
  		while (s < e) {
  			if (str.charAt(s) != str.charAt(e)) {
  				return false;
  			}
  			s++;
  			e--;
  		}
  		return true;
  	}
  
  	private static void reverse(int[] arr, int s, int e) {
  		while (s < e) {
  			int temp = arr[s];
  			arr[s++] = arr[e];
  			arr[e--] = temp;
  		}
  	}
  
  	private static int getMax(int[] arr, int s, int e) {
  		int maxi = s;
  		for (int i = s + 1; i <= e; i++) {
  			if (arr[i] > arr[maxi]) {
  				maxi = i;
  			}
  		}
  		return maxi;
  	}
  
  	private static int getMin(int[] arr, int s, int e) {
  		int mini = s;
  		for (int i = s + 1; i <= e; i++) {
  			if (arr[i] < arr[mini]) {
  				mini = i;
  			}
  		}
  		return mini;
  	}
  
  	// ******LOWEST COMMON MULTIPLE************************
  	private static long lcm(long n1, long n2) {
  		return (n1 * n2) / gcd(n1, n2);
  	}
  
  	private static int lcm(int n1, int n2) {
  		return (n1 * n2) / gcd(n1, n2);
  	}
  
  	// ***********GCD*****************
  	private static long gcd(long num1, long num2) {
  		if (num2 == 0) {
  			return num1;
  		}
  		return gcd(num2, num1 % num2);
  	}
  
  	private static int gcd(int num1, int num2) {
  		if (num2 == 0) {
  			return num1;
  		}
  		return gcd(num2, num1 % num2);
  	}
  
  	// **************PRIME FACTORIZE **********************************//
  	static TreeMap<Long, Long> prime(long n) {
  		TreeMap<Long, Long> h = new TreeMap<>();
  		long num = n;
  		for (int i = 2; i <= Math.sqrt(num); i++) {
  			if (n % i == 0) {
  				long nt = 0L;
  				while (n % i == 0) {
  					n = n / i;
  					nt++;
  				}
  				h.put(i * 1L, nt);
  			}
  		}
  		if (n != 1)
  			h.put(n, 1L);
  		return h;
  
  	}
  
  	// ****CLASS PAIR ************************************************
  	static class Pair implements Comparable<Pair> {
  		int vtx;
  		int wt;
  
  		Pair(int x, int y) {
  			this.vtx = x;
  			this.wt = y;
  		}
  
  		public int compareTo(Pair o) {
  			return this.wt - o.wt;
  
  		}
  
  	}
  
  	static class InputReader {
  		private InputStream stream;
  		private byte[] buf = new byte[1024];
  		private int curChar;
  		private int numChars;
  		private SpaceCharFilter filter;
  
  		public InputReader(InputStream stream) {
  			this.stream = stream;
  		}
  
  		public int read() {
  			if (numChars == -1)
  				throw new InputMismatchException();
  			if (curChar >= numChars) {
  				curChar = 0;
  				try {
  					numChars = stream.read(buf);
  				} catch (IOException e) {
  					throw new InputMismatchException();
  				}
  				if (numChars <= 0)
  					return -1;
  			}
  			return buf[curChar++];
  		}
  
  		public int Int() {
  			int c = read();
  			while (isSpaceChar(c))
  				c = read();
  			int sgn = 1;
  			if (c == '-') {
  				sgn = -1;
  				c = read();
  			}
  			int res = 0;
  			do {
  				if (c < '0' || c > '9')
  					throw new InputMismatchException();
  				res *= 10;
  				res += c - '0';
  				c = read();
  			} while (!isSpaceChar(c));
  			return res * sgn;
  		}
  
  		public String String() {
  			int c = read();
  			while (isSpaceChar(c))
  				c = read();
  			StringBuilder res = new StringBuilder();
  			do {
  				res.appendCodePoint(c);
  				c = read();
  			} while (!isSpaceChar(c));
  			return res.toString();
  		}
  
  		public boolean isSpaceChar(int c) {
  			if (filter != null)
  				return filter.isSpaceChar(c);
  			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  		}
  
  		public String next() {
  			return String();
  		}
  
  		public interface SpaceCharFilter {
  			public boolean isSpaceChar(int ch);
  		}
  	}
  
  	static class OutputWriter {
  		private final PrintWriter writer;
  
  		public OutputWriter(OutputStream outputStream) {
  			writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
  		}
  
  		public OutputWriter(Writer writer) {
  			this.writer = new PrintWriter(writer);
  		}
  
  		public void print(Object... objects) {
  			for (int i = 0; i < objects.length; i++) {
  				if (i != 0)
  					writer.print(' ');
  				writer.print(objects[i]);
  			}
  		}
  
  		public void println(Object... objects) {
  			print(objects);
  			writer.println();
  		}
  
  		public void close() {
  			writer.close();
  		}
  
  		public void flush() {
  			writer.flush();
  		}
  	}
  
  //*****************INPUT PATTERN******************************************
  	public static int i() {
  		return in.Int();
  	}
  
  	public static long l() {
  		String s = in.String();
  		return Long.parseLong(s);
  	}
  
  	public static String s() {
  		return in.String();
  	}
  
  	public static int[] readArray(int n) {
  		int A[] = new int[n];
  		for (int i = 0; i < n; i++) {
  			A[i] = i();
  		}
  		return A;
  	}
  
  	public static long[] readArray(long n) {
  		long A[] = new long[(int) n];
  		for (int i = 0; i < n; i++) {
  			A[i] = l();
  		}
  		return A;
  	}
  
  }
  