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 

// upsolve with rainboy
import java.io.*;
import java.util.*;

public class CF920E {
	static Random rand = new Random();
	static class V {
		V l, r;
		int key;
		int x;
		V(int key) {
			this.key = key;
			x = rand.nextInt();
		}
	}
	static V v_, l_, r_;
	static void split(V v, int key) {
		if (v == null) {
			v_ = l_ = r_ = null;
		} else if (v.key < key) {
			split(v.r, key);
			v.r = l_; l_ = v;
		} else if (v.key > key) {
			split(v.l, key);
			v.l = r_; r_ = v;
		} else {
			v_ = v;
			l_ = v.l;
			r_ = v.r;
			v.l = v.r = null;
		}
	}
	static V merge(V l, V r) {
		if (l == null)
			return r;
		if (r == null)
			return l;
		if (l.x <= r.x) {
			l.r = merge(l.r, r);
			return l;
		} else {
			r.l = merge(l, r.l);
			return r;
		}
	}
	static V first(V v) {
		if (v != null)
			while (v.l != null)
				v = v.l;
		return v;
	}
	static void tr_add(int key) {
		split(v_, key);
		if (v_ == null)
			v_ = new V(key);
		v_ = merge(merge(l_, v_), r_);
	}
	static void tr_remove(int key) {
		split(v_, key);
		v_ = merge(l_, r_);
	}
	static V tr_higher(int key) {
		split(v_, key);
		V v = first(r_);
		v_ = merge(merge(l_, v_), r_);
		return v;
	}
	static ArrayList[] aa;
	static int dfs(int i) {
		ArrayList<Integer> a = aa[i];
		int m = a.size(), c = 1;
		for (int h = 0; h < m - 1; h++) {
			int p = a.get(h), q = a.get(h + 1);
			while (true) {
				V v = tr_higher(p);
				if (v == null || v.key >= q)
					break;
				tr_remove(v.key);
				c += dfs(v.key);
			}
		}
		return c;
	}
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(System.out);
		StringTokenizer st = new StringTokenizer(br.readLine());
		int n = Integer.parseInt(st.nextToken());
		int m = Integer.parseInt(st.nextToken());
		aa = new ArrayList[n];
		for (int i = 0; i < n; i++) {
			aa[i] = new ArrayList<Integer>();
			aa[i].add(-1);
			aa[i].add(n);
		}
		while (m-- > 0) {
			st = new StringTokenizer(br.readLine());
			int i = Integer.parseInt(st.nextToken()) - 1;
			int j = Integer.parseInt(st.nextToken()) - 1;
			aa[i].add(j);
			aa[j].add(i);
		}
		for (int i = 0; i < n; i++)
			Collections.sort(aa[i]);
		for (int i = 0; i < n; i++)
			tr_add(i);
		ArrayList<Integer> cc = new ArrayList<>();
		while (v_ != null) {
			V v = first(v_);
			int i = v.key;
			tr_remove(i);
			cc.add(dfs(i));
		}
		pw.println(cc.size());
		Collections.sort(cc);
		for (int c : cc)
			pw.print(c + " ");
		pw.println();
		pw.close();
	}
}
