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
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3 6
4 6
 11 49
10 3
6 4
11 3
7 6
10 6
6 1
4 3
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9 7
2 11
8 6
3 9
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9 5
6 5
1 4
11 9
1 7
8 10
3 6
3 7
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6 9
4 10
8 7
4 9
8 2
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7 4
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 5 4
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 10 36
7 8
7 9
2 3
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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
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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.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class Connected {


    private static Set<Integer> unvisited;

    private static List<Integer> components;

    private static boolean[] visited;

    private static Map<Integer, Set<Integer>> antiEdges;

    public static void main(String[] args) throws Exception {

        BufferedReader bs = new BufferedReader(new InputStreamReader(System.in));
        String[] ve = bs.readLine().split(" ");
        int vertices = Integer.parseInt(ve[0]);
        int edges = Integer.parseInt(ve[1]);
        visited = new boolean[vertices+1];

        antiEdges = new HashMap<>();

        unvisited = new TreeSet<>();

        components = new ArrayList<>();

        for(int i=1;i<vertices+1;i++) {
            antiEdges.put(i, new TreeSet<>());
            unvisited.add(i);
        }

        for(int i=0;i<edges;i++) {
            String[] ve1 = bs.readLine().split(" ");
            int v = Integer.parseInt(ve1[0]);
            int w = Integer.parseInt(ve1[1]);

            Set<Integer> antiV = antiEdges.get(v);
            antiV.add(w);
            antiEdges.put(v, antiV);

            Set<Integer> antiW = antiEdges.get(w);
            antiW.add(v);
            antiEdges.put(w, antiW);
        }

        for(int i=1;i<=vertices;i++) {
            if(!visited[i]) {
                components.add(bfs(i));
            }
        }

        System.out.println(components.size());
        Collections.sort(components);
        System.out.print(components.get(0));
        for(int i=1;i<components.size();i++) {
            System.out.print(" " + components.get(i));
        }

    }

    private static int bfs(int start) {
        int res = 0;
        Stack<Integer> s = new Stack<>();
        s.push(start);

        while(!s.empty()) {
            int top = s.pop();
            if(visited[top]) continue;
            visited[top] = true;
            res++;
            unvisited.remove(top);
            Set<Integer> antiAdj = antiEdges.get(top);
            for(Integer i: new ArrayList<>(unvisited)) {
                if(antiAdj.contains(i)) continue;
                if(!visited[i]) {
                    s.push(i);
                    unvisited.remove(i);
                }
            }

        }
        return res;
    }
}
