2583

import java.util.*;
 
class pos{
	int x,y;
	
	pos(int x, int y) {
		this.x = x;
		this.y = y;
	}
}

public class Main {
	
	public static int M,N,K;
	public static int[][] square;
	public static int[][] paper;
	public static int[][] checked;
	public static int[] dx = {-1,1,0,0};
	public static int[] dy = {0,0,-1,1};
	public static int cnt=0;
	
    public static void main(String[] args) {
    
    	Scanner sc = new Scanner(System.in);
    	
    	M = sc.nextInt();
    	N = sc.nextInt();
    	K = sc.nextInt();
    	
    	paper = new int[M][N];
    	checked = new int[M][N];
    	square = new int[K][4];
    	
    	for(int i=0; i<K; i++) {
    		square[i][0] = sc.nextInt();
    		square[i][1] = sc.nextInt();
    		square[i][2] = sc.nextInt();
    		square[i][3] = sc.nextInt();
    	}
    	
    	
    	int[] temp = new int[M*N];
    	
    	for(int i=0; i<M; i++) {
    		for(int j=0; j<N; j++) {
    			if(!rec(i,j) && checked[i][j]==0) {
    				//체크
//    				System.out.println("bfs 시작" + i+" "+ j);
    				temp[cnt] = bfs(i,j);
    				cnt++;
    				//체크
 //   				System.out.println("bfs 끝" + i+" "+ j);
    			}
    		}
    	}
    	
    	int[] area = new int[cnt];
    	for(int i=0; i<cnt; i++)
    		area[i] = temp[i];
    	
    	Arrays.sort(area);
    	
    	System.out.println(cnt);
    	for(int i=0; i<area.length; i++)
    		System.out.print(area[i]+" ");
    	
    	sc.close();
    }
    
    // 직사각형에 포함되어 있는지 -> true
    public static boolean rec(int x,int y) {
    	boolean result = false;
    	
    	for(int i=0; i<K; i++) {
    		if(y>=square[i][0] && y<square[i][2] && x>=square[i][1] && x<square[i][3]) {
    			result = true;
    			break;
    		}
    	}
    	
    	return result;
    }
    
    public static int bfs(int x, int y) {
    	Queue <pos> q = new LinkedList<pos>();
    	checked[x][y] = 1;
    	q.add(new pos(x,y));
    	
    	int ax,ay;
    	int sum = 1;
    	
    	while(!q.isEmpty()) {
    		pos now = q.poll();
    		
    		for(int i=0; i<4; i++) {
    			ax = now.x + dx[i];
    			ay = now.y + dy[i];
    			
    			if(!rec(ax,ay)) {
    				if(ax>=0 && ay>=0 && ax<M && ay<N) {
    					if(checked[ax][ay] == 0) {
    						
    						//체크
//    						System.out.println(ax +" "+ay+"에서 카운팅");
	    					
		    				checked[ax][ay] = 1;
		    				q.add(new pos(ax,ay));
		    				sum++;
    					}
    				}
    			}
    		}
    	}
    	
    	return sum;
    }
    
}