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
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3 2
5 8
8 9
1 3
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5 3
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4 11
1 11
8 3
 5 4
1 4
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1 3
1 4
2 3
 10 36
7 8
7 9
2 3
2 4
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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
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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
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 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 

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author dipankar12
 */
import java.io.*;
import java.util.*;
public class r37e {
    public static void main(String args[])
    {
        fastio in=new fastio(System.in);
        PrintWriter pw=new PrintWriter(System.out);

        int n=in.nextInt();
        int m=in.nextInt();
        
        r37e1 ob=new r37e1(n);
        for(int i=0;i<m;i++)
            ob.remEdge(in.nextInt(), in.nextInt());
        
        System.out.println("Hi");
        boolean visited[]=new boolean[n+1];
        LinkedList<Integer> ll=new LinkedList<Integer>();
        for(int i=1;i<=n;i++)
        {
            HashSet<Integer> hs=new HashSet<Integer>();
            if(!visited[i])
            {
                hs=ob.bfs(i, visited);
                ll.add(hs.size());
                hs.clear();
            }
        }
        
        Collections.sort(ll);
        Iterator<Integer> it=ll.iterator();
        pw.println(ll.size());
        while(it.hasNext())
            pw.print(it.next()+" ");
        pw.close();
    }

    static class fastio {
     
            private final InputStream stream;
            private final byte[] buf = new byte[8192];
            private int cchar, snchar;
            private SpaceCharFilter filter;
     
            public fastio(InputStream stream) {
                this.stream = stream;
            }
     
            public int nxt() {
                if (snchar == -1)
                    throw new InputMismatchException();
                if (cchar >= snchar) {
                    cchar = 0;
                    try {
                        snchar = stream.read(buf);
                    } catch (IOException e) {
                        throw new InputMismatchException();
                    }
                    if (snchar <= 0)
                        return -1;
                }
                return buf[cchar++];
            }
     
            public int nextInt() {
                int c = nxt();
                while (isSpaceChar(c)) {
                    c = nxt();
                }
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = nxt();
                }
                int res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = nxt();
                } while (!isSpaceChar(c));
                return res * sgn;
            }
     
            public long nextLong() {
                int c = nxt();
                while (isSpaceChar(c)) {
                    c = nxt();
                }
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = nxt();
                }
                long res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = nxt();
                } while (!isSpaceChar(c));
                return res * sgn;
            }
     
            public int[] nextIntArray(int n) {
                int a[] = new int[n];
                for (int i = 0; i < n; i++) {
                    a[i] = nextInt();
                }
                return a;
            }
     
            public String readString() {
                int c = nxt();
                while (isSpaceChar(c)) {
                    c = nxt();
                }
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = nxt();
                } while (!isSpaceChar(c));
                return res.toString();
            }
     
            public String nextLine() {
                int c = nxt();
                while (isSpaceChar(c))
                    c = nxt();
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = nxt();
                } while (!isEndOfLine(c));
                return res.toString();
            }
     
            public boolean isSpaceChar(int c) {
                if (filter != null)
                    return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
            }
     
            private boolean isEndOfLine(int c) {
                return c == '\n' || c == '\r' || c == -1;
            }
     
            public interface SpaceCharFilter {
                public boolean isSpaceChar(int ch);
            }
        }
    

}
class r37e1
{
    private LinkedList<Integer> adj[];
    public r37e1(int n)
    {
        adj=new LinkedList[n+1];
        for(int i=1;i<=n;i++)
        {
            adj[i]=new LinkedList();
            for(int j=1;j<=n;j++)
                if(i!=j)
                    adj[i].add(j);
        }
    }
    void remEdge(int u,int v)
    {
        adj[u].remove(adj[u].indexOf(v));
        adj[v].remove(adj[v].indexOf(u));
    }
    HashSet<Integer> bfs(int n, boolean visited[])
    {
        HashSet<Integer> hs=new HashSet<Integer>();
        LinkedList<Integer> ll=new LinkedList<Integer>();
        ll.add(n);
        hs.add(n);
        visited[n]=true;
        while(!ll.isEmpty())
        {
            int x=ll.poll();
            Iterator<Integer> it=adj[x].iterator();
            while(it.hasNext())
            {
                int p=it.next();
                if(!visited[p])
                {
                    visited[p]=true;
                    hs.add(p);
                    ll.add(p);
                }
            }
        }
        return hs;
    }
}
