7 20
4 6
6 7
4 5
1 2
2 4
1 7
3 5
2 1
6 2
6 1
7 3
3 2
3 6
3 1
3 4
2 5
1 6
7 4
6 3
7 5
 8 23
1 2
1 4
1 6
1 8
2 3
2 4
2 5
2 6
2 7
2 8
3 4
3 5
3 6
3 7
3 8
4 5
4 6
4 7
5 6
5 7
5 8
6 8
7 8
 4 4
2 1
3 1
1 4
3 2
 8 18
1 4
1 6
1 7
2 3
2 4
2 5
2 6
2 7
2 8
3 4
3 8
4 7
5 6
5 7
5 8
6 7
6 8
7 8
 10 34
7 10
2 3
2 4
2 5
9 10
2 7
2 8
2 10
4 5
4 6
4 7
4 8
4 9
6 7
6 8
6 9
6 10
1 2
1 3
1 5
8 9
1 6
1 7
1 8
1 9
1 10
3 4
3 5
3 6
3 8
3 10
5 6
5 9
5 10
 5 7
1 2
2 3
3 4
1 5
2 5
3 5
4 5
 2 0
 8 23
2 7
7 5
8 6
8 2
6 3
3 5
8 1
8 4
8 3
3 4
1 2
2 6
5 2
6 4
7 6
6 5
7 8
7 1
5 4
3 7
1 4
3 1
3 2
 2 1
1 2
 6 9
1 2
1 4
1 5
2 3
2 5
2 6
3 5
4 6
5 6
 12 56
9 5
2 6
9 8
5 4
1 11
1 6
4 1
1 10
10 3
8 4
5 1
9 1
5 10
2 7
11 5
6 11
5 8
7 6
3 2
12 7
8 6
12 3
1 2
8 1
2 11
10 12
4 6
5 12
2 4
10 2
7 3
12 11
7 10
7 1
9 2
11 9
9 10
8 7
11 3
7 9
5 7
4 12
3 5
12 2
4 10
9 12
5 2
9 4
11 8
8 2
3 6
4 11
8 10
6 10
3 9
3 4
 12 58
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 10
1 11
1 12
2 3
2 4
2 5
2 6
2 7
2 8
2 9
2 10
2 11
2 12
3 4
3 5
3 6
3 7
3 8
3 9
3 10
3 11
3 12
4 5
4 6
4 8
4 11
4 12
5 6
5 7
5 8
5 9
5 10
5 11
6 7
6 8
6 9
6 10
6 11
6 12
7 8
7 9
7 10
7 11
7 12
8 9
8 10
8 11
9 10
9 11
9 12
10 12
 4 3
2 1
3 1
4 2
 3 1
2 3
 6 10
1 2
1 3
1 4
1 6
2 3
2 4
2 5
3 5
3 6
4 6
 11 49
10 3
6 4
11 3
7 6
10 6
6 1
4 3
10 2
4 5
9 2
10 1
5 7
1 5
9 7
2 11
8 6
3 9
2 5
9 5
6 5
1 4
11 9
1 7
8 10
3 6
3 7
11 5
6 9
4 10
8 7
4 9
8 2
4 2
8 11
7 4
9 10
8 1
10 7
3 2
5 8
8 9
1 3
2 7
10 11
5 3
10 5
4 11
1 11
8 3
 5 4
1 4
2 3
4 3
4 2
 4 3
1 2
3 1
4 3
 4 3
1 3
1 4
2 3
 10 36
7 8
7 9
2 3
2 4
2 5
9 10
2 7
2 8
2 9
2 10
4 5
4 6
4 7
4 8
4 10
6 7
6 9
6 10
1 2
1 3
1 4
8 9
1 5
8 10
1 7
1 8
1 9
1 10
3 4
3 6
3 7
3 9
5 6
5 7
5 9
5 10
 8 15
2 1
4 5
2 4
3 4
2 5
3 5
2 6
3 6
5 6
4 6
2 7
3 8
2 8
3 7
6 7

3
1 2 4 
 3
1 2 5 
 2
1 3 
 1
8 
 1
10 
 2
1 4 
 1
2 
 3
1 3 4 
 2
1 1 
 1
6 
 3
1 4 7 
 4
1 1 1 9 
 1
4 
 1
3 
 1
6 
 5
1 1 1 2 6 
 1
5 
 1
4 
 1
4 
 2
2 8 
 1
8 

import java.util.*;
import java.io.*;
import java.math.*;
public class Solution{
    
    static Subset[] subsets;
    
    static class Node{
        int id;
        HashSet<Integer> forbiden = new HashSet<Integer>();
        Node(int id){
            this.id = id;
        }
    }
    
    static Node[] node;
    static int n;
    
    static TreeSet<Integer> ts = new TreeSet<Integer>();
    
    static void dfs(int nod){
        
        int i = ts.higher(0);
        while(i!=n+1){
            if(!node[nod].forbiden.contains(i)){
                
                ts.remove(i);
                union(nod,i);
                dfs(i);
                
            }
            i = ts.higher(i);
        }
        
    }
    
    static class Subset{
        int parent;
        int rank;
        public Subset(int p,int r){
            parent = p;
            rank = r;
        }
    }
    
    static int find(int i){
        if(subsets[i].parent!=i) subsets[i].parent = find(subsets[i].parent);
        return subsets[i].parent;
    }
    
    static void union(int x,int y){
        int xroot = find(x);
        int yroot = find(y);
        if(subsets[xroot].rank<subsets[yroot].rank) subsets[xroot].parent = yroot;
        else if(subsets[xroot].rank>subsets[yroot].rank) subsets[yroot].parent = xroot;
        else {
            subsets[xroot].parent = yroot;
            subsets[yroot].rank++;
        }
    }
    
    public static void main(String[] args)throws IOException{
                
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        
        PrintWriter out = new PrintWriter(System.out);
        
        n = Integer.parseInt(st.nextToken());
        int m = Integer.parseInt(st.nextToken());
        
        subsets = new Subset[n+1];
        for(int i=1;i<=n;i++){
            subsets[i] = new Subset(i,0);
        }
        
        node = new Node[n+1];
        for(int i=1;i<=n;i++) node[i] = new Node(i);
        
        for(int i=1;i<=n+1;i++) ts.add(i);
        
        for(int i=0;i<m;i++){
            st = new StringTokenizer(br.readLine());
            int x = Integer.parseInt(st.nextToken());
            int y = Integer.parseInt(st.nextToken());
            node[x].forbiden.add(y);
            node[y].forbiden.add(x);
        }
        
        for(int i=1;i<=n;i++){
            
            if(ts.contains(i)){
                ts.remove(i);
                dfs(i);
            }
            
        }
        
        int[] nb = new int[n+1];
        for(int i=1;i<=n;i++) nb[find(i)]++;
        int k = 0;
        
        for(int i=1;i<=n;i++){
            if(nb[i]!=0) k++;
        }
        
        out.println(k);
        int[] g = new int[k];
        int pos = 0;
        for(int i=1;i<=n;i++){
            if(nb[i]!=0) {
                g[pos] = nb[i];
                pos++;
            }
        }
        
        Arrays.sort(g);
        for(int i=0;i<k;i++) out.print(g[i]+" ");
        out.println("");

        out.flush();
        
    }
    
}