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.ArrayList;
  import java.util.Arrays;
  import java.util.StringTokenizer;
  import java.util.List;
   import java.util.*;
   public class realfast implements Runnable 
    {
      private static final int INF = (int) 1e9;
      long in= 1000000007;
      long fac[]= new long[1000001];
      long inv[]=new long[1000001];
      public  void solve() throws IOException 
      {
         
              int n = readInt();
              int m1 = readInt();
              int m2 = readInt();
              int parent1[]=new int[n+1];
              int parent2[]=new int[n+1];
              for(int i=1;i<=n;i++)
              {
                  parent1[i]=i;
                  parent2[i]=i;
              }
              for(int i =0;i<m1;i++)
              {
                  int u = readInt();
                  int v = readInt();
                  union(parent1,u,v);
              }
              for(int i =0;i<m2;i++)
              {
                  int u = readInt();
                  int v = readInt();
                  union(parent2,u,v);
              }
              ArrayList<edge>e = new ArrayList<edge>();
              for(int i=1;i<=n;i++)
              {
                  for(int j=i+1;j<=n;j++)
                  {
                      if(check(parent1,i,j)&&check(parent2,i,j))
                      {
                          e.add(new edge(i,j));
                          union(parent1,i,j);
                          union(parent2,i,j);
                      }
                  }
              }
  
              out.println(e.size());
              for(int i =0;i<e.size();i++)
              {
                  out.println(e.get(i).u+" "+e.get(i).v);
              }
          
         
  
      }
      public boolean check(int parent[] , int i , int j )
      {
          int par1= find(parent,i);
          int par2= find(parent,j);
          if(par1!=par2)
              return true;
          else
              return false;
  
  
      }
       public void union(int parent[] , int i , int j )
      {
          int par1= find(parent,i);
          int par2= find(parent,j);
          if(par1==par2)
              return ;
  
          parent[par1]=par2;
  
  
      }
      public int find(int parent[] , int i  )
      {
          if(parent[i]==i)
              return i;
  
          parent[i]= find(parent,parent[i]);
          return parent[i];
  
      }
     
      public long query(long seg[] , int left, int right , int index, int l , int r)
      {   
           long inf = 100000000;
           inf = inf*inf;
          if(left>=l&&right<=r)
          {
              return seg[index];
          }
          if(l>right||left>r)
              return inf;
          int mid = left+(right-left)/2;
          return Math.min(query(seg,left,mid,2*index+1,l,r),query(seg,mid+1,right,2*index+2,l,r));
  
      }
      
      public int value (int seg[], int left , int right ,int index, int l, int r)
      {
              
              if(left>right)
              {
                return -100000000;
              }
              if(right<l||left>r)
                  return -100000000;
              if(left>=l&&right<=r)
                  return seg[index];
              int mid = left+(right-left)/2;
              int val = value(seg,left,mid,2*index+1,l,r);
              int val2 = value(seg,mid+1,right,2*index+2,l,r);
              return Math.max(val,val2);
  
      }
     
      public int gcd(int a , int b )
      {
        if(a<b)
        {
          int t =a;
          a=b;
          b=t;
        }
        if(a%b==0)
          return b ;
        return gcd(b,a%b);
      }
      public long pow(long n , long p,long m)
      {
           if(p==0)
              return 1;
          long val = pow(n,p/2,m);;
          val= (val*val)%m;
          if(p%2==0)
              return val;
          else
              return (val*n)%m;
      }
      
      
      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
      public static void main(String[] args) {
          new Thread(null, new realfast(), "", 128 * (1L << 20)).start();
      }
   
      private static final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
      private BufferedReader reader;
      private StringTokenizer tokenizer;
      private PrintWriter out;
   
      @Override
      public void run() {
          try {
              if (ONLINE_JUDGE || !new File("input.txt").exists()) {
                  reader = new BufferedReader(new InputStreamReader(System.in));
                  out = new PrintWriter(System.out);
              } else {
                  reader = new BufferedReader(new FileReader("input.txt"));
                  out = new PrintWriter("output.txt");
              }
              solve();
          } catch (IOException e) {
              throw new RuntimeException(e);
          } finally {
              try {
                  reader.close();
              } catch (IOException e) {
                  // nothing
              }
              out.close();
          }
      }
   
      private String readString() throws IOException {
          while (tokenizer == null || !tokenizer.hasMoreTokens()) {
              tokenizer = new StringTokenizer(reader.readLine());
          }
          return tokenizer.nextToken();
      }
   
      @SuppressWarnings("unused")
      private int readInt() throws IOException {
          return Integer.parseInt(readString());
      }
   
      @SuppressWarnings("unused")
      private long readLong() throws IOException {
          return Long.parseLong(readString());
      }
   
      @SuppressWarnings("unused")
      private double readDouble() throws IOException {
          return Double.parseDouble(readString());
      }
  }
  class edge implements Comparable<edge>{
      int u ;
      int v;
      
      edge(int  u, int v)
      {
         this.u=u;
         this.v=v;
      }
      public int compareTo(edge e)
      {
          return this.v-e.v;
      }
  }