Area

import java.util.Scanner;
import java.util.*;
public class Main{
    public static ArrayList<Integer> answer = new ArrayList();
    public static int score=0;
    public static int[] dx = new int[]{0,1,0,-1};
    public static int[] dy = new int[]{1,0,-1,0};
    public static int sero,garo,distriction;
    public static int[][] map;
    public static boolean[][] visit;
    public static void main(String[] args){

       // Please Enter Your Code Here
      Scanner scan = new Scanner(System.in);
      input(scan);
      area();
      scan.close();
    }
    
    public static void bfs(int x,int y)
    {
      score=0;
      Queue<Point> q = new LinkedList();
      q.add(new Point(x,y));
      visit[x][y]=true;
      
      while(!q.isEmpty())
      {
        Point pt = q.peek();
        score+=1;
        q.remove();
        int cx = pt.x;
        int cy = pt.y;
        
        for(int i=0;i<4;i++)
        {
          int nx = cx+dx[i];
          int ny = cy+dy[i];
          
          if(nx>=0 && ny>=0 && nx<sero && ny<garo)
          {
            if(visit[nx][ny]==false && map[nx][ny]==0)
            {
              visit[nx][ny]=true;
              q.add(new Point(nx,ny));
             
            }
          }
        }
        
      }
       answer.add(score);
    }
    
    public static void area()
    {
      int dCnt=0;
      // printMap();
      for(int i=0;i<sero;i++)
      {
        for(int j=0;j<garo;j++)
        {
          if(map[i][j]!=1 && visit[i][j]==false)
          {
            // visit[i][j]=true;
            bfs(i,j);
            dCnt++;
          }
        }
      }
      
      Collections.sort(answer);
      System.out.println(dCnt);
      for(int i=0;i<answer.size();i++)
      {
        System.out.print(answer.get(i)+" ");
      }System.out.println();
    }
    
    public static void printMap()
    {
        for(int i=0;i<sero;i++)
        {
          for(int j=0;j<garo;j++)
          {
            System.out.print(map[i][j]+" ");
          }System.out.println();
        }
    }
    
    public static void input(Scanner scan)
    {
      sero = scan.nextInt();garo=scan.nextInt();distriction=scan.nextInt();
      map = new int[sero][garo]; visit = new boolean[sero][garo];
      
      for(int i=0;i<distriction;i++)
      {
        int a = scan.nextInt();int b = scan.nextInt();int c = scan.nextInt();int d = scan.nextInt();
        for(int j=b;j<d;j++)
        {
          for(int k=a;k<c;k++)
          {
            map[j][k]=1;
          }
        }
      }
    }
}

class Point
{
  int x;int y;
  public Point(int x,int y)
  {
    this.x = x;this.y =y;
  }
}