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.util.*;
  import java.io.*;
  // import java.lang.*;
  // import java.math.*;
  
  public class Codeforces {
      static FastReader sc=new FastReader();
  	static PrintWriter out=new PrintWriter(System.out);
  	static long mod=1000000007;
  	static long mod1=998244353;
  	static int MAX=Integer.MAX_VALUE;
  	static int MIN=Integer.MIN_VALUE;
  	static long MAXL=Long.MAX_VALUE;
  	static long MINL=Long.MIN_VALUE;
  	static ArrayList<Integer> graph[];
  	public static void main (String[] args) throws java.lang.Exception
  	{
  		// code goes here
  		// int t=I();
  		// while(t-->0)
  		// {
  			
  		// }
  		int n=I(),m1=I(),m2=I();
  		DSU d1=new DSU(n);
  		DSU d2=new DSU(n);
  		for(int i=0;i<m1;i++){
  			int u=I(),v=I();
  			d1.union(u,v);
  		}
  		for(int i=0;i<m2;i++){
  			int u=I(),v=I();
  			d2.union(u,v);
  		}
  		// printArray(d1.par);
  		// printArray(d2.par);
  		ArrayList<Integer> a1=new ArrayList<>();
  		ArrayList<Integer> a2=new ArrayList<>();
  		for(int i=1;i<=n;i++){
  			for(int j=i+1;j<=n;j++){
  				int a=d1.find(i),b=d1.find(j);
  				// out.println("a->"+a+" b->"+b);
  				if(a==b)continue;
  				int c=d2.find(i),d=d2.find(j);
  				// out.println("c->"+c+" d->"+d);
  				if(c==d)continue;
  				
  				a1.add(i);
  				a2.add(j);
  				d1.union(i,j);
  				d2.union(i,j);
  			}
  		}
  		// printArrayI(a1);
  		// printArrayI(a2);
  		if(a1.size()==0)out.println("0");
  		else{
  			out.println(a1.size());
  			for(int i=0;i<a1.size();i++){
  				out.println(a1.get(i)+" "+a2.get(i));
  			}
  		}
  		out.close();
  	}
  	public static class pair
      {
      	int a;
      	int b;
      	public pair(int val,int index)
      	{
      	    a=val;
      	    b=index;
      	}
      }
  	public static class myComp implements Comparator<pair>
  	{
  		//sort in ascending order.
  		public int compare(pair p1,pair p2)
  		{
  			if(p1.a==p2.a)
      	    return 0;
      	    else if(p1.a<p2.a)
      	    return -1;
      	    else
      	    return 1;
  		}
  		//sort in descending order.
  		// public int compare(pair p1,pair p2)
      	// {
      	//     if(p1.a==p2.a)
      	//     return 0;
      	//     else if(p1.a<p2.a)
      	//     return 1;
      	//     else
      	//     return -1;
      	// }
  	}
  	public static long kadane(long a[],int n)
  	{
  		long max_sum=Long.MIN_VALUE,max_end=0;
  		for(int i=0;i<n;i++){
  			max_end+=a[i];
  			if(max_sum<max_end){max_sum=max_end;}
  			if(max_end<0){max_end=0;}
  		}
  		return max_sum;
  	}
  	public static void DFS(int s,boolean visited[])
  	{
  		visited[s]=true;
  		for(int i:graph[s]){
  			if(!visited[i]){
  				DFS(i,visited);
  			}
  		}
  	}
  	public static void setGraph(int n,int m)
  	{
  		graph=new ArrayList[n+1];
  		for(int i=0;i<=n;i++){
  			graph[i]=new ArrayList<>();
  		}
  		for(int i=0;i<m;i++){
  			int u=I(),v=I();
  			graph[u].add(v);
  			graph[v].add(u);
  		}
  	}
  	public static int BS(long a[],long x,int ii,int jj)
  	{
  		// int n=a.length;
  		int mid=0;
  		int i=ii,j=jj;
  		while(i<=j)
  		{
  			mid=(i+j)/2;
  			if(a[mid]<x){
  				i=mid+1;
  			}else if(a[mid]>x){
  				j=mid-1;
  			}else{
  				return mid;
  			}
  		}
  		return -1;
  	}
  	public static int lower_bound(int arr[],int s, int N, int X)
  	{
  		if(arr[N]<X)return N;
  		if(arr[0]>X)return -1;
  		int left=s,right=N;
  		while(left<right){
  			int mid=(left+right)/2;
  			if(arr[mid]==X)
  			return mid;
  			else if(arr[mid]>X){
  				if(mid>0 && arr[mid]>X && arr[mid-1]<=X){
  					return mid-1;
  				}else{
  					right=mid-1;
  				}
  			}else{
  				if(mid<N && arr[mid+1]>X && arr[mid]<=X){
  					return mid;
  				}else{
  					left=mid+1;
  				}
  			}
  		}
  		return left;
  	}
  	public static ArrayList<Integer> primeSieve(int n)
  	{
  	    ArrayList<Integer> arr=new ArrayList<>();
  	    boolean prime[] = new boolean[n + 1];
          for (int i = 0; i <= n; i++)
          prime[i] = true;
          for (int p = 2; p * p <= n; p++)
          {
              if (prime[p] == true)
              {
                  for (int i = p * p; i <= n; i += p)
                  prime[i] = false;
              }
          }
          for (int i = 2; i <= n; i++)
          {
              if (prime[i] == true)
              arr.add(i);
          }
          return arr;
  	}
  
  	// Fenwick / BinaryIndexed  Tree  USE IT - FenwickTree ft1=new FenwickTree(n);
  	public static class FenwickTree
  	{
  		int farr[];
  		int n;
  		public FenwickTree(int c)
  		{
  			n=c+1;
  			farr=new int[n];
  		}
  		// public void update_range(int l,int r,long p)
  		// {
  		// 	update(l,p);
  		// 	update(r+1,(-1)*p);
  		// }
  		public void update(int x,int p)
  		{
  			for(;x<=n;x+=x&(-x))
  			{
  				farr[x]+=p;
  			}
  		}
  		public long get(int x)
  		{
  			long ans=0;
  			for(;x>0;x-=x&(-x))
  			{
  				ans=ans+farr[x];
  			}
  			return ans;
  		}
  	}
  
  	//Disjoint Set Union
  	public static class DSU
  	{
  	    int par[],rank[];
  	    public DSU(int c)
  	    {
  	        par=new int[c+1];
  	        rank=new int[c+1];
  	        for(int i=0;i<=c;i++)
  	        {
  	            par[i]=i;
  	            rank[i]=0;
  	        }
  	    }
  	    public int find(int a)
  	    {
  	        if(a==par[a])
  	        return a;
  	        return par[a]=find(par[a]);
  	    }
  	    public void union(int a,int b)
  	    {
  	        int a_rep=find(a),b_rep=find(b);
  	        if(a_rep==b_rep)
  	        return;
  	        if(rank[a_rep]<rank[b_rep])
  	        par[a_rep]=b_rep;
  	        else if(rank[a_rep]>rank[b_rep])
  	        par[b_rep]=a_rep;
  	        else
  	        {
  	            par[b_rep]=a_rep;
  	            rank[a_rep]++;
  	        }
  	    }
  	}
  
  	//SEGMENT TREE CODE
  
  	// public static void segmentUpdate(int si,int ss,int se,int qs,int qe,long x)
  	// {
  	// 	if(ss>qe || se<qs)return;
  	// 	if(qs<=ss && qe>=se)
  	// 	{
  	// 		seg[si][0]+=1L;
  	// 		seg[si][1]+=x*x;
  	// 		seg[si][2]+=2*x;
  	// 		return;
  	// 	}
  	// 	int mid=(ss+se)/2;
  	// 	segmentUpdate(2*si+1,ss,mid,qs,qe,x);
  	// 	segmentUpdate(2*si+2,mid+1,se,qs,qe,x);
  	// }
  	// public static long segmentGet(int si,int ss,int se,int x,long f,long s,long t,long a[])
  	// {
  	// 	if(ss==se && ss==x)
  	// 	{
  	// 		f+=seg[si][0];
  	// 		s+=seg[si][1];
  	// 		t+=seg[si][2];
  	// 		long ans=a[x]+(f*((long)x+1L)*((long)x+1L))+s+(t*((long)x+1L));
  	// 		return ans;
  	// 	}
  	// 	int mid=(ss+se)/2;
  	// 	if(x>mid){
  	// 		return segmentGet(2*si+2,mid+1,se,x,f+seg[si][0],s+seg[si][1],t+seg[si][2],a);
  	// 	}else{
  	// 		return segmentGet(2*si+1,ss,mid,x,f+seg[si][0],s+seg[si][1],t+seg[si][2],a);
  	// 	}
  	// }
  
  	
      public static class myComp1 implements Comparator<pair1>
      {
  		//sort in ascending order.
      	public int compare(pair1 p1,pair1 p2)
      	{
      	    if(p1.a==p2.a)
      	    return 0;
      	    else if(p1.a<p2.a)
      	    return -1;
      	    else
      	    return 1;
      	}
  		//sort in descending order.
  		// public int compare(pair p1,pair p2)
      	// {
      	//     if(p1.a==p2.a)
      	//     return 0;
      	//     else if(p1.a<p2.a)
      	//     return 1;
      	//     else
      	//     return -1;
      	// }
      }
  	public static class pair1
      {
      	long a;
      	long b;
  		int p;
      	public pair1(long val,long index,int i)
      	{
      	    a=val;
      	    b=index;
  			p=i;
      	}
      }
      public static ArrayList<pair1> mergeIntervals(ArrayList<pair1> arr)
  	{
  	    //****************use this in main function-Collections.sort(arr,new myComp1());
  	    ArrayList<pair1> a1=new ArrayList<>();
  	    if(arr.size()<=1)
  	    return arr;
  	    a1.add(arr.get(0));
  	    int i=1,j=0;
  	    while(i<arr.size())
  	    {
  	        if(a1.get(j).b<arr.get(i).a)
  	        {
  	           a1.add(arr.get(i));
  	           i++;
  	           j++;
  	        }
  	        else if(a1.get(j).b>arr.get(i).a && a1.get(j).b>=arr.get(i).b)
  	        {
  	            i++;
  	        }
  	        else if(a1.get(j).b>=arr.get(i).a)
  	        {
  	            long a=a1.get(j).a;
  	            long b=arr.get(i).b;
  	            a1.remove(j);
  	            a1.add(new pair1(a,b,-1));
  	            i++;
  	        }
  	    }
  	    return a1;
  	}
  	public static boolean isPalindrome(String s,int n)
  	{
  		for(int i=0;i<=n/2;i++){
  			if(s.charAt(i)!=s.charAt(n-i-1)){
  				return false;
  			}
  		}
  		return true;
  	}
  	public static int gcd(int a,int b)
  	{
  	    if(b==0)
  	    return a;
  	    else
  	    return gcd(b,a%b);
  	}
  	public static long gcd(long a,long b)
  	{
  	    if(b==0)
  	    return a;
  	    else
  	    return gcd(b,a%b);
  	}
  	public static long fact(long n)
  	{
  		long fact=1;
  		for(long i=2;i<=n;i++){
  			fact=((fact%mod)*(i%mod))%mod;
  		}
  		return fact;
  	}
  	public static long fact(int n)
  	{
  		long fact=1;
  		for(int i=2;i<=n;i++){
  			fact=((fact%mod)*(i%mod))%mod;
  		}
  		return fact;
  	} 
  	public static boolean isPrime(int n) 
  	{ 
  	    if (n <= 1) 
  	        return false; 
  	    if (n <= 3) 
  	        return true; 
  	    if (n % 2 == 0 || n % 3 == 0) 
  	        return false; 
  	    double sq=Math.sqrt(n);
  	  
  	    for (int i = 5; i <= sq; i = i + 6) 
  	        if (n % i == 0 || n % (i + 2) == 0) 
  	            return false; 
  	    return true; 
  	} 
      public static boolean isPrime(long n) 
  	{ 
  	    if (n <= 1) 
  	        return false; 
  	    if (n <= 3) 
  	        return true; 
  	    if (n % 2 == 0 || n % 3 == 0) 
  	        return false; 
  	    double sq=Math.sqrt(n);
  	
  	    for (int i = 5; i <= sq; i = i + 6) 
  	        if (n % i == 0 || n % (i + 2) == 0) 
  	            return false; 
  	    return true; 
  	}
  	public static void printArray(long a[])
  	{
  		for(int i=0;i<a.length;i++){
  			out.print(a[i]+" ");
  		}
  		out.println();
  	}
  	public static void printArray(int a[])
  	{
  		for(int i=0;i<a.length;i++){
  			out.print(a[i]+" ");
  		}
  		out.println();
  	}
  	public static void printArray(char a[])
  	{
  		for(int i=0;i<a.length;i++){
  			out.print(a[i]);
  		}
  		out.println();
  	}
  	public static void printArray(String a[])
  	{
  		for(int i=0;i<a.length;i++){
  			out.print(a[i]+" ");
  		}
  		out.println();
  	}
  	public static void printArray(boolean a[])
  	{
  		for(int i=0;i<a.length;i++){
  			out.print(a[i]+" ");
  		}
  		out.println();
  	}
  	public static void printArray(int a[][])
  	{
  		for(int i=0;i<a.length;i++){
  			for(int j=0;j<a[i].length;j++){
  				out.print(a[i][j]+" ");
  			}out.println();
  		}
  	}
  	public static void printArray(long a[][])
  	{
  		for(int i=0;i<a.length;i++){
  			for(int j=0;j<a[i].length;j++){
  				out.print(a[i][j]+" ");
  			}out.println();
  		}
  	}
  	public static void printArray(char a[][])
  	{
  		for(int i=0;i<a.length;i++){
  			for(int j=0;j<a[i].length;j++){
  				out.print(a[i][j]+" ");
  			}out.println();
  		}
  	}
  	public static void printArrayL(ArrayList<Long> arr)
  	{
  		for(int i=0;i<arr.size();i++){
  			out.print(arr.get(i)+" ");
  		}
  		out.println();
  	}
  	public static void printArrayI(ArrayList<Integer> arr)
  	{
  		for(int i=0;i<arr.size();i++){
  			out.print(arr.get(i)+" ");
  		}
  		out.println();
  	}
  	public static void printArrayS(ArrayList<String> arr)
  	{
  		for(int i=0;i<arr.size();i++){
  			out.print(arr.get(i)+" ");
  		}
  		out.println();
  	}
  	public static void printMapInt(HashMap<Integer,Integer> hm){
  		for(Map.Entry<Integer,Integer> e:hm.entrySet()){
  			out.println(e.getKey()+"->"+e.getValue());
  		}out.println();
  	}
  	public static void printMapLong(HashMap<Long,Long> hm){
  		for(Map.Entry<Long,Long> e:hm.entrySet()){
  			out.println(e.getKey()+"->"+e.getValue());
  		}out.println();
  	}
  
  	//Modular Arithmetic
  
  	public static long add(long a,long b)
  	{
  		a+=b;
  		if(a>=mod)a-=mod;
  		return a;
  	}
  	public static long sub(long a,long b)
  	{
  		a-=b;
  		if(a<0)a+=mod;
  		return a;
  	}
  	public static long mul(long a,long b)
  	{
  		return ((a%mod)*(b%mod))%mod;
  	}
  	public static long divide(long a,long b,long m)
  	{
  		a=mul(a,modInverse(b,m));
  		return a;
  	}
  	public static long modInverse(long a,long m)
  	{
  		int x=0,y=0;
  		own p=new own(x,y);
  		long g=gcdExt(a,m,p);
  		if(g!=1){
  			out.println("inverse does not exists");
  			return -1;
  		}else{
  			long res=((p.a%m)+m)%m;
  			return res;
  		}
  	}
  	public static long gcdExt(long a,long b,own p)
  	{
  		if(b==0){
  			p.a=1;
  			p.b=0;
  			return a;
  		}
  		int x1=0,y1=0;
  		own p1=new own(x1,y1);
  		long gcd=gcdExt(b,a%b,p1);
  		p.b=p1.a - (a/b) * p1.b;
  		p.a=p1.b;
  		return gcd;
  	}
  	public static long pwr(long m,long n)
  	{
  		long res=1;
  		m=m%mod;
  		if(m==0)
  		return 0;
  		while(n>0)
  		{
  			if((n&1)!=0)
  			{
  				res=(res*m)%mod;
  			}
  			n=n>>1;
  			m=(m*m)%mod;
  		}
  		return res;
  	}
  	public static class own
      {
      	long a;
      	long b;
      	public own(long val,long index)
      	{
      	    a=val;
      	    b=index;
      	}
      }
  
  	//Modular Airthmetic
  
  	public static void sort(int[] A)
  	{
          int n = A.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i)
  		{
              int tmp = A[i];
              int randomPos = i + rnd.nextInt(n-i);
              A[i] = A[randomPos];
              A[randomPos] = tmp;
          }
          Arrays.sort(A);
      }
      public static void sort(long[] A)
  	{
  	    int n = A.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i)
  		{
              long tmp = A[i];
              int randomPos = i + rnd.nextInt(n-i);
              A[i] = A[randomPos];
              A[randomPos] = tmp;
          }
  	    Arrays.sort(A);
  	}
  	public static int I(){return sc.I();}
      public static long L(){return sc.L();}
      public static String S(){return sc.S();}
      public static double D(){return sc.D();}
  }
  class FastReader {  
      BufferedReader br;
      StringTokenizer st;
      public FastReader(){
          br = new BufferedReader(new InputStreamReader(System.in));
      }
      String next(){
          while (st == null || !st.hasMoreElements()){
              try {
                  st = new StringTokenizer(br.readLine());
              }
              catch (IOException e){
                  e.printStackTrace();
              }
          }
          return st.nextToken();
      }
      int I(){ 
          return Integer.parseInt(next());
      }
      long L(){ 
          return Long.parseLong(next());
      }
      double D(){
           return Double.parseDouble(next());
      }
      String S(){
          String str = "";
          try 
          {
              str = br.readLine();
          }
          catch (IOException e)
          {
              e.printStackTrace();
          }
          return str;
      }
  }
  