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 

//package Codes.Codeforces.ED37;
import java.util.*;
import java.io.*;
public class E {
        String INPUT = "5 5 1 2 3 4 3 2 4 2 2 5";
        Set<Integer> s1 = new HashSet<>();
        Set<Integer> s2 = new HashSet<>();
        void solve()
        {
                int n = i(),m = i();
                int[] from = new int[m];
                int[] to = new int[m];
                for (int i = 0; i < m; i++) {
                        from[i] = i()-1;
                        to[i] = i()-1;
                }
                int[][] g = arrayGraphU(from,to,n);
                for (int i = 0; i <n ; i++) {
                        s1.add(i);
                }
                int[] ans = new int[n];int k=0;
                for (int i = 0; i < n; i++) {
                        if(!s1.contains(i)) continue;
                        ans[k++] = bfs(i,g);
                }
                ans = Arrays.copyOf(ans,k);
                Arrays.sort(ans);
                out.println(k);
                Arrays.stream(ans).forEach(e->out.print(e+" "));
        }
        private int bfs(int i,int[][] g)
        {
                int ans = 1;
                s1.remove(i);
                Queue<Integer> q = new LinkedList<>();
                q.add(i);
                while(!q.isEmpty())
                {
                        int now = q.poll();
                        for(int x: g[now])
                        {
                                if(!s1.contains(x)) continue;
                                s1.remove(x);
                                s2.add(x);
                        }
                        for(int x: s1)
                        {
                                q.add(x);
                                ans++;
                        }
                        s1.clear();
                        s1.addAll(s2);
                        s2.clear();
                }
                return ans;
        }
        private int[][] arrayGraphU(int[] f, int[] t, int n) {
                int[][] graph = new int[n][];
                int[] p = new int[n];
                for (int from : f) {
                        p[from]++;
                }
                for (int to : t) {
                        p[to]++;
                }
                for (int i = 0; i < n; i++) {
                        graph[i] = new int[p[i]];
                }
                for (int i = 0; i < f.length; i++) {
                        graph[f[i]][--p[f[i]]] = t[i];
                        graph[t[i]][--p[t[i]]] = f[i];
                }
                return graph;

        }
        void run() throws Exception{
                is = oj ? System.in: new ByteArrayInputStream(INPUT.getBytes());
                //is = System.in;
                out = new PrintWriter(System.out);
                long s = System.currentTimeMillis();
                solve();
                out.flush();
                tr(System.currentTimeMillis()-s+"ms");
        }
        public static void main(String[] args)throws Exception {
                new E().run();
        }
        InputStream is;
        PrintWriter out;
        private byte[] inbuf = new byte[1024];
        public int lenbuf = 0, ptrbuf = 0;

        private int readByte()
        {
                if(lenbuf == -1)throw new InputMismatchException();
                if(ptrbuf >= lenbuf){
                        ptrbuf = 0;
                        try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
                        if(lenbuf <= 0)return -1;
                }
                return inbuf[ptrbuf++];
        }

        private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
        private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

        private double d() { return Double.parseDouble(s()); }
        private char c() { return (char)skip(); }

        private String s()
        {
                int b = skip();
                StringBuilder sb = new StringBuilder();
                while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
                        sb.appendCodePoint(b);
                        b = readByte();
                }
                return sb.toString();
        }

        private char[] sa(int n)
        {
                char[] buf = new char[n];
                int b = skip(), p = 0;
                while(p < n && !(isSpaceChar(b))){
                        buf[p++] = (char)b;
                        b = readByte();
                }
                return n == p ? buf : Arrays.copyOf(buf, p);
        }

        private char[][] nm(int n, int m)
        {
                char[][] map = new char[n][];
                for(int i = 0;i < n;i++)map[i] = sa(m);
                return map;
        }

        private int[] ia(int n)
        {
                int[] a = new int[n];
                for(int i = 0;i < n;i++)a[i] = i();
                return a;
        }

        private int i()
        {
                int num = 0, b;
                boolean minus = false;
                while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
                if(b == '-'){
                        minus = true;
                        b = readByte();
                }

                while(true){
                        if(b >= '0' && b <= '9'){
                                num = num * 10 + (b - '0');
                        }else{
                                return minus ? -num : num;
                        }
                        b = readByte();
                }
        }

        private long l()
        {
                long num = 0;
                int b;
                boolean minus = false;
                while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
                if(b == '-'){
                        minus = true;
                        b = readByte();
                }

                while(true){
                        if(b >= '0' && b <= '9'){
                                num = num * 10 + (b - '0');
                        }else{
                                return minus ? -num : num;
                        }
                        b = readByte();
                }
        }

        private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
        private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }

}
