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.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.lang.reflect.Array;
  import java.util.*;
  public class Main{
      static class FastScanner {
              BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
              StringTokenizer st = new StringTokenizer("");
  
              String next() {
                  while (!st.hasMoreTokens())
                      try {
                          st = new StringTokenizer(br.readLine());
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  return st.nextToken();
              }
  
              int nextInt() {
                  return Integer.parseInt(next());
              }
  
              int[] nextArray(int n) {
                  int[] a = new int[n];
                  for (int i = 0; i < n; i++) a[i] = nextInt();
                  return a;
              }
              long[] nextArray(long n) {
                  long[] a = new long[(int) n];
                  for (int i = 0; i < n; i++) a[i] = nextLong();
                  return a;
              }
  
              long nextLong() {
                  return Long.parseLong(next());
              }
          }
      static class FastWriter extends PrintWriter {
              FastWriter(){
                  super(System.out);
              }
              void println(int[] array) {
                  for(int i=0; i<array.length; i++) {
                      print(array[i]+" ");
                  }
                  println();
              }
              void println(long [] array) {
                  for(int i=0; i<array.length; i++) {
                      print(array[i]+" ");
                  }
                  println();
              }
          }
      static int MOD=1000003,n;
      static int[] rank1,parent1,rank2,parent2;
      public static void main(String[] args) throws IOException {
          FastScanner in = new FastScanner();
          FastWriter out = new FastWriter();
          //int t=in.nextInt();
          int t=1;
          while (t-->0){
              n=in.nextInt();
              int m1=in.nextInt();
              int m2=in.nextInt();
              rank1=new int[n];
              rank2=new int[n];
              parent1=new int[n];
              parent2=new int[n];
              makeSet();
              for (int i = 0; i < m1; i++) {
                  int u=in.nextInt()-1;
                  int v=in.nextInt()-1;
                  union1(u,v);
              }
              for (int i = 0; i < m2; i++) {
                  int u=in.nextInt()-1;
                  int v=in.nextInt()-1;
                  union2(u,v);
              }
              ArrayList<ArrayList<Integer>> list=new ArrayList<>();
              for (int i = 0; i < n; i++) {
                  for (int j = 0; j < n; j++) {
                      if(find1(i)!=find1(j)&&find2(i)!=find2(j)){
                          ArrayList<Integer> ll=new ArrayList<>();
                          ll.add(i+1);ll.add(j+1);list.add(ll);
                          union1(i,j);
                          union2(i,j);
                      }
                  }
              }
              out.println(list.size());
              for(ArrayList<Integer> ll:list){
                  out.println(ll.get(0)+" "+ll.get(1));
              }
          }
          out.close();
      }
      static void makeSet() {
          for (int i = 0; i < n; i++) {
              parent1[i]=i;
              parent2[i]=i;
          }
      }
      static int find1(int x){
          if (parent1[x] != x) {
              parent1[x] = find1(parent1[x]);
          }
          return parent1[x];
      }
      static int find2(int x){
          if (parent2[x] != x) {
              parent2[x] = find2(parent2[x]);
          }
          return parent2[x];
      }
      static void union1(int x, int y) {
          int xRoot = find1(x), yRoot = find1(y);
          if (xRoot == yRoot){
              return;
          }
          if (rank1[xRoot] < rank1[yRoot]){
              parent1[xRoot] = yRoot;
          }else if (rank1[yRoot] < rank1[xRoot]){
              parent1[yRoot] = xRoot;
          }else{
              parent1[yRoot] = xRoot;
              rank1[xRoot] = rank1[xRoot] + 1;
          }
      }
      static void union2(int x, int y) {
          int xRoot = find2(x), yRoot = find2(y);
          if (xRoot == yRoot){
              return;
          }
          if (rank2[xRoot] < rank2[yRoot]){
              parent2[xRoot] = yRoot;
          }else if (rank2[yRoot] < rank2[xRoot]){
              parent2[yRoot] = xRoot;
          }else{
              parent2[yRoot] = xRoot;
              rank2[xRoot] = rank2[xRoot] + 1;
          }
      }
      static int count(String a, String b) {
          int m = a.length();
          int n = b.length();
          int lookup[][] = new int[m + 1][n + 1];
          for (int i = 0; i <= n; ++i){
              lookup[0][i] = 0;
          }
          for (int i = 0; i <= m; ++i){
              lookup[i][0] = 1;
          }
          for (int i = 1; i <= m; i++) {
              for (int j = 1; j <= n; j++) {
                  if (a.charAt(i - 1) == b.charAt(j - 1)){
                      lookup[i][j] = lookup[i - 1][j - 1] + lookup[i - 1][j];
                  }else{
                      lookup[i][j] = lookup[i - 1][j];
                  }
                  if(lookup[i][j]>=1000000007){
                      lookup[i][j]-=1000000007;
                  }
              }
          }
  
          return lookup[m][n];
      }
      static void BFS(ArrayList<Integer>[] adj, int src, int[] dist, int[] paths, int n) {
          boolean[] visited = new boolean[n];
          for (int i = 0; i < n; i++){
              visited[i] = false;
          }
          dist[src] = 0;
          paths[src] = 1;
          Queue<Integer> q = new LinkedList<>();
          q.add(src);
          visited[src] = true;
          while (!q.isEmpty()) {
              int curr = q.peek();
              q.poll();
              for (int x : adj[curr]) {
                  if (!visited[x]) {
                      q.add(x);
                      visited[x] = true;
                  }
                  if (dist[x] > dist[curr] + 1) {
                      dist[x] = dist[curr] + 1;
                      paths[x] = paths[curr];
                  } else if (dist[x] == dist[curr] + 1){
                      paths[x] += paths[curr];
                  }
                  if(paths[x]>=1000000007){
                      paths[x]-=1000000007;
                  }
              }
          }
      }
      static void findShortestPaths(ArrayList<Integer>[] adj, int s, int n) {
          int[] dist = new int[n], paths = new int[n];
          for (int i = 0; i < n; i++){
              dist[i] = Integer.MAX_VALUE;
          }
          for (int i = 0; i < n; i++){
              paths[i] = 0;
          }
          BFS(adj, s, dist, paths, n);
          System.out.println((paths[n-1])%1000000007);
      }
      //Arrays.sort(a, (o1, o2) -> (o1[0] - o2[0]));
      static int totalPrimeFactors(int n) {
          int cnt=0;
          while (n%2==0) {
              cnt++;
              n /= 2;
          }
          int num= (int) Math.sqrt(n);
          for (int i = 3; i <= num; i+= 2) {
              while (n%i == 0) {
                  cnt++;
                  n /= i;
                  num=(int)Math.sqrt(n);
              }
          }
          if (n > 2){
              cnt++;
          }
          return cnt;
      }
      static char get(int i){
          return (char)(i+'a');
      }
      static boolean distinct(int num){
          HashSet<Integer> set=new HashSet<>();
          int len=String.valueOf(num).length();
          while (num!=0){
              set.add(num%10);
              num/=10;
          }
          return set.size()==len;
      }
      static int maxSubArraySum(int a[]) {
          int n=a.length,max=a[0],sum=a[0];
          for (int i = 1; i < n; i++) {
              sum=Math.max(sum+a[i],a[i]);
              max=Math.max(max,sum);
          }
          return max;
      }
      static void segmentedSieve(ArrayList<Integer> res,int low, int high) {
          if(low < 2){
              low = 2;
          }
          ArrayList<Integer> prime = new ArrayList<>();
          sS2(high, prime);
          boolean[] mark = new boolean[high - low + 1];
          Arrays.fill(mark, true);
          for (int i = 0; i < prime.size(); i++) {
              int loLim = (low / prime.get(i)) * prime.get(i);
              if (loLim < low){
                  loLim += prime.get(i);
              }
              if (loLim == prime.get(i)){
                  loLim += prime.get(i);
              }
              for (int j = loLim; j <= high; j += prime.get(i)) {
                  mark[j - low] = false;
              }
          }
          for (int i = low; i <= high; i++) {
              if (mark[i - low]){
                  System.out.println(i);
                  res.add(i);
              }
          }
      }
      static void sS2(int limit, ArrayList<Integer> prime) {
          int bound = (int)Math.sqrt(limit);
          boolean[] mark = new boolean[bound + 1];
          for (int i = 0; i <= bound; i++){
              mark[i] = true;
          }
          for (int i = 2; i * i <= bound; i++) {
              if (mark[i]) {
                  for (int j = i * i; j <= bound; j += i){
                      mark[j] = false;
                  }
              }
          }
          for (int i = 2; i <= bound; i++) {
              if (mark[i]){
                  prime.add(i);
              }
          }
      }
      static boolean[] sieveOfEratosthenes(int n){
          boolean[] prime = new boolean[n + 1];
          Arrays.fill(prime,true);
          prime[0]=false;prime[1]=false;
          for (int p = 2; p * p <= n; p++) {
              if(prime[p]){
                  for (int i = p * p; i <= n; i += p){
                      prime[i] = false;
                  }
              }
          }
          return prime;
      }
      static int highestPowerOf2(int n) {
          if (n < 1){ return 0; }
          int res = 1;
          for (int i = 0; i < 8 * Integer.BYTES; i++) {
              int curr = 1 << i;
              if (curr > n){ break; }
              res = curr;
          }
          return res;
      }
      static int reduceFraction(int x, int y) {
          int d= gcd(x, y);
          return x/d+y/d;
      }
      static boolean subset(int[] ar,int n,int sum){
          if(sum==0){
              return true;
          }
          if(n<0||sum<0){
              return false;
          }
          return subset(ar,n-1,sum)||subset(ar,n-1,sum-ar[n]);
      }
      static boolean isPrime(int n){
          if(n<=1) return false;
          for(int i = 2;i<=Math.sqrt(n);i++){
              if (n % i == 0) return false;
          }
          return true;
      }
      static int gcd(int a, int b) {
          if (b == 0) return a;
          return gcd(b, a % b);
      }
      static long gcd(long a, long b) {
          if (b == 0) return a;
          return gcd(b, a % b);
      }
      static long lcm(long a, long b) {
          return (a * b) / gcd(a, b);
      }
      static int lcm(int a, int b) {
          return (a * b) / gcd(a, b);
      }
      static boolean isPowerOfTwo(long n) {
          if(n==0){
              return false;
          }
          while (n%2==0){
              n/=2;
          }
          return n==1;
      }
      static boolean isPerfectSquare(int x){
          if (x >= 0) {
              int sr = (int)Math.sqrt(x);
              return ((sr * sr) == x);
          }
          return false;
      }
      static int lower_bound(int[] arr, int x) {
          int low_limit = 0, high_limit = arr.length, mid;
          while (low_limit < high_limit) {
              mid = (low_limit + high_limit) / 2;
              if (arr[mid] >= x){
                  high_limit = mid;
              }else{
                  low_limit = mid + 1;
              }
          }
          return low_limit;
      }
      static int upper_bound(int[] arr, int x) {
          int low_limit = 0, high_limit = arr.length, mid;
          while (low_limit < high_limit) {
              mid = (low_limit + high_limit) / 2;
              if (arr[mid] > x){
                  high_limit = mid;
              }else{
                  low_limit = mid + 1;
              }
          }
          return low_limit;
      }
      static int binarySearch(int[] ar,int n,int num){
          int low=0,high=n-1;
          while (low<=high){
              int mid=(low+high)/2;
              if(ar[mid]==num){
                  return mid;
              }else if(ar[mid]>num){
                  high=mid-1;
              }else {
                  low=mid+1;
              }
          }
          return -1;
      }
      static int fib(int n) {
          long[][] F = new long[][]{{1,1},{1,0}};
          if (n == 0){
              return 0;
          }
          power(F, n-1);
          return (int)F[0][0];
      }
      static void multiply(long F[][], long M[][]) {
          long x =  (F[0][0]*M[0][0])%1000000007 + (F[0][1]*M[1][0])%1000000007;
          long y =  (F[0][0]*M[0][1])%1000000007 + (F[0][1]*M[1][1])%1000000007;
          long z =  (F[1][0]*M[0][0])%1000000007 + (F[1][1]*M[1][0])%1000000007;
          long w =  (F[1][0]*M[0][1])%1000000007 + (F[1][1]*M[1][1])%1000000007;
          F[0][0] = x%1000000007;
          F[0][1] = y%1000000007;
          F[1][0] = z%1000000007;
          F[1][1] = w%1000000007;
      }
      static void power(long F[][], int n) {
          if( n == 0 || n == 1){
              return;
          }
          long M[][] = new long[][]{{1,1},{1,0}};
          power(F, n/2);
          multiply(F, F);
          if (n%2 != 0){
              multiply(F, M);
          }
      }
      static int binaryExponentiation(int x,int n){
          int ans=1;
          while (n>0){
              if(n%2!=0){
                  ans=(ans*x)%MOD;
              }
              x=(x*x)%MOD;
              n/=2;
          }
          return ans;
      }
      static void bfs(ArrayList<Integer>[] ar,int node){
          boolean[] visited=new boolean[ar.length];
          Queue<Integer> queue=new LinkedList<>();
          visited[node]=true;
          queue.add(node);
          while(!queue.isEmpty()){
              int nn=queue.poll();
              System.out.print(nn+" ");
              for(int n : ar[nn]) {
                  if (!visited[n]) {
                      visited[n] = true;
                      queue.add(n);
                  }
              }
          }
          System.out.println();
      }
      static void dfs(ArrayList<Integer>[] ar,int node){
          boolean[] visited=new boolean[ar.length];
          dfsUtil(ar,node,visited);
          System.out.println();
      }
      static void dfsUtil(ArrayList<Integer>[] ar,int node,boolean[] visited){
          visited[node]=true;
          //System.out.print(node+" ");
          for(Integer n:ar[node]){
              if(!visited[n]){
                  dfsUtil(ar,n,visited);
              }
          }
      }
  }