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;
template <class T>
inline void amin(T& x, const T& y) {
  if (y < x) x = y;
}
template <class T>
inline void amax(T& x, const T& y) {
  if (x < y) x = y;
}
using LL = long long;
using PII = pair<int, int>;
using VI = vector<int>;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const int MAXN = 5005;
int n, m;
int find(VI& f, int x) { return x == f[x] ? x : f[x] = find(f, f[x]); }
void uni(VI& f, VI& sz, int x, int y) {
  int fx = find(f, x), fy = find(f, y);
  if (fx != fy) {
    f[fx] = fy;
    sz[fy] += sz[fx];
  }
}
void MAIN() {
  cin >> n >> m;
  vector<PII> es(m);
  VI deg(n);
  for (int i = (0); i < (m); i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    es[i].first = u;
    es[i].second = v;
    deg[u]++;
    deg[v]++;
  }
  int min_i = 0;
  for (int i = (0); i < (n); i++)
    if (deg[i] < deg[min_i]) min_i = i;
  VI vis(n);
  for (auto& e : es) {
    int u = e.first, v = e.second;
    if (u == min_i) vis[v] = 1;
    if (v == min_i) vis[u] = 1;
  }
  int blk = 0;
  VI rem;
  for (int i = (0); i < (n); i++)
    if (!vis[i])
      blk++;
    else
      rem.push_back(i);
  int k = (int)rem.size();
  map<int, int> id;
  for (int i = (0); i < (k); i++) id[rem[i]] = i;
  vector<VI> g(k + 1, VI(k + 1));
  for (auto& e : es) {
    int u = e.first, v = e.second;
    u = id.find(u) == id.end() ? k : id[u];
    v = id.find(v) == id.end() ? k : id[v];
    if (u != v) g[u][v] = g[v][u] = 1;
  }
  VI f(k + 1);
  VI sz(k + 1, 1);
  sz[k] = blk;
  for (int i = (0); i < (k + 1); i++) f[i] = i;
  for (int i = (0); i < (k + 1); i++)
    for (int j = (0); j < (k + 1); j++)
      if (!g[i][j]) uni(f, sz, i, j);
  VI res;
  for (int i = (0); i < (k + 1); i++)
    if (sz[i] && find(f, i) == i) res.push_back(sz[i]);
  sort(res.begin(), res.end());
  cout << (int)res.size() << endl;
  for (auto& v : res) cout << v << " ";
  cout << endl;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int TC = 1;
  for (int tc = (0); tc < (TC); tc++) {
    MAIN();
  }
  return 0;
}
