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 

#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int mo = 19260817;
int head[100005 << 1], k;
struct Edge {
  int v;
  int next;
} edge[100005 << 2];
struct union_find_set {
  int root;
  int num;
} ufs[100005 << 1];
void init(int n) {
  for (int i = 1; i <= n; i++) ufs[i].root = i, ufs[i].num = 1;
}
int find(int x) {
  return x == ufs[x].root ? x : ufs[x].root = find(ufs[x].root);
}
void uni(int x, int y) {
  int xroot = find(x);
  int yroot = find(y);
  if (xroot != yroot) {
    if (ufs[xroot].num >= ufs[yroot].num) {
      ufs[yroot].root = xroot;
      ufs[xroot].num += ufs[yroot].num;
    } else {
      ufs[xroot].root = yroot;
      ufs[yroot].num += ufs[xroot].num;
    }
  }
}
void add(int u, int v) {
  edge[k].v = v;
  edge[k].next = head[u];
  head[u] = k++;
}
void bfs(int n) {
  queue<int> q;
  vector<int> vec;
  set<int> s1, s2;
  for (int i = 2; i <= n; i++) s1.insert(i);
  q.push(1);
  while (!q.empty() || !s1.empty()) {
    int u = q.front();
    q.pop();
    s2.clear();
    vec.clear();
    for (int i = head[u]; i != -1; i = edge[i].next) {
      int v = edge[i].v;
      s2.insert(v);
    }
    for (auto it = s1.begin(); it != s1.end(); it++) {
      if (s2.find(*it) == s2.end()) {
        q.push(*it);
        uni(u, *it);
        vec.push_back(*it);
      }
    }
    for (auto it = vec.begin(); it != vec.end(); it++) s1.erase(*it);
    if (q.empty()) {
      int tmp = -1;
      for (auto it = s1.begin(); it != s1.end(); it++) {
        q.push(*it);
        tmp = *it;
        break;
      }
      if (tmp != -1) s1.erase(tmp);
    }
  }
}
int ans[100005 << 1];
int main() {
  int n, m, u, v, cnt;
  while (~scanf("%d%d", &n, &m)) {
    k = cnt = 0;
    memset(head, -1, sizeof(head));
    init(n);
    while (m--) {
      scanf("%d%d", &u, &v);
      add(u, v);
      add(v, u);
    }
    bfs(n);
    for (int i = 1; i <= n; i++)
      if (i == find(i)) ans[cnt++] = ufs[i].num;
    sort(ans, ans + cnt);
    printf("%d\n", cnt);
    for (int i = 0; i < cnt; i++)
      printf("%d%c", ans[i], i == cnt - 1 ? '\n' : ' ');
  }
  return 0;
}
