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.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.TreeSet;
import java.util.ArrayList;
import java.util.TreeMap;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.Comparator;
import java.util.Collections;
import java.io.InputStream;
/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskE solver = new TaskE();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskE {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.readInt();
            int m = in.readInt();
            Vertex[] vertices = new Vertex[n];
            for (int i = 0; i < vertices.length; i++) {
                vertices[i] = new Vertex(i);
            }
            for (int i = 0; i < m; i++) {
                int x = in.readInt() - 1;
                int y = in.readInt() - 1;
                vertices[x].notAdj.add(y);
                vertices[y].notAdj.add(x);
            }
            Arrays.sort(vertices, Comparator.comparing((Vertex vertex) -> vertex.notAdj.size()));
            // vertices[0].notAdj is capped at 500 or less
            TreeMap<Integer, Integer> translate = new TreeMap<>();
            TreeMap<Integer, Integer> reverseTranslate = new TreeMap<>();
            for (int val : vertices[0].notAdj) translate.put(val, 0);
            int ptr = 0;
            for (int val : translate.keySet()) {
                translate.put(val, ptr);
                reverseTranslate.put(ptr, val);
                ptr++;
            }
            TreeSet<Integer> big = new TreeSet<>();
            for (int i = 0; i < n; i++) {
                if (!translate.containsKey(i)) {
                    big.add(i);
                }
            }
            Arrays.sort(vertices, Comparator.comparing((Vertex vertex) -> vertex.index));
            boolean[][] adj = new boolean[translate.size()][translate.size()];
            ArrayUtils.fill(adj, true);
            for (int idx : translate.keySet()) {
                for (int other : vertices[idx].notAdj) {
                    if (translate.containsKey(other)) {
                        adj[translate.get(idx)][translate.get(other)] = false;
                        adj[translate.get(other)][translate.get(idx)] = false;
                    }
                }
            }
            RecursiveIndependentSetSystem iss = new RecursiveIndependentSetSystem(n);
            for (int i = 0; i < adj.length; i++) {
                for (int j = 0; j < adj.length; j++) {
                    if (adj[i][j]) {
                        iss.join(i, j);
                    }
                }
            }
            TreeMap<Integer, ArrayList<Integer>> counts = new TreeMap<>();
            for (int i = 0; i < adj.length; i++) {
                int key = iss.get(i);
                if (!counts.containsKey(key)) counts.put(key, new ArrayList<>());
                counts.get(key).add(i);
            }
            ArrayList<Integer> values = new ArrayList<>();
            for (ArrayList<Integer> set : counts.values()) {
                boolean ok = true;
                for (int untrans : set) {
                    int normal = reverseTranslate.get(untrans);
                    int hitCount = 0;
                    for (int act : vertices[normal].notAdj) {
                        if (big.contains(act)) {
                            hitCount++;
                        }
                    }
                    if (hitCount < big.size()) {
                        ok = false;
                    }
                }
                if (!ok) {
                    for (int val : set) {
                        big.add(reverseTranslate.get(val));
                    }
                } else {
                    values.add(set.size());
                }
            }
            values.add(big.size());
            Collections.sort(values);
            out.printLine(values.size());
            for (int val : values) {
                out.print(val + " ");
            }
            out.printLine();
        }

        class Vertex {
            int index;
            ArrayList<Integer> notAdj = new ArrayList<>();

            public Vertex(int index) {
                this.index = index;
            }
        }
    }
    static class ArrayUtils {
        public static void fill(boolean[][] array, boolean value) {
            for (boolean[] row : array) {
                Arrays.fill(row, value);
            }
        }
    }
    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }
    static interface IndependentSetSystem {
        public static interface Listener {
            public void joined(int joinedRoot, int root);
        }
    }
    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void printLine() {
            writer.println();
        }

        public void close() {
            writer.close();
        }

        public void printLine(int i) {
            writer.println(i);
        }
    }
    static class RecursiveIndependentSetSystem implements IndependentSetSystem {
        private final int[] color;
        private final int[] rank;
        private int setCount;
        private IndependentSetSystem.Listener listener;

        public RecursiveIndependentSetSystem(int size) {
            color = new int[size];
            rank = new int[size];
            for (int i = 0; i < size; i++) {
                color[i] = i;
            }
            setCount = size;
        }

        public RecursiveIndependentSetSystem(RecursiveIndependentSetSystem other) {
            color = other.color.clone();
            rank = other.rank.clone();
            setCount = other.setCount;
        }

        public boolean join(int first, int second) {
            first = get(first);
            second = get(second);
            if (first == second) {
                return false;
            }
            if (rank[first] < rank[second]) {
                int temp = first;
                first = second;
                second = temp;
            } else if (rank[first] == rank[second]) {
                rank[first]++;
            }
            setCount--;
            color[second] = first;
            if (listener != null) {
                listener.joined(second, first);
            }
            return true;
        }

        public int get(int index) {
            int start = index;
            while (color[index] != index) {
                index = color[index];
            }
            while (start != index) {
                int next = color[start];
                color[start] = index;
                start = next;
            }
            return index;
        }
    }
}

