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
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8 6
12 3
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4 6
5 12
2 4
10 2
7 3
12 11
7 10
7 1
9 2
11 9
9 10
8 7
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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
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1 2
1 3
1 4
1 6
2 3
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3 5
3 6
4 6
 11 49
10 3
6 4
11 3
7 6
10 6
6 1
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6 9
4 10
8 7
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8 2
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7 8
7 9
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2 7
2 8
2 9
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4 6
4 7
4 8
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6 7
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8 9
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1 7
1 8
1 9
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3 7
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2 1
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2 4
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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 
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1 1 
 1
6 
 3
1 4 7 
 4
1 1 1 9 
 1
4 
 1
3 
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6 
 5
1 1 1 2 6 
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5 
 1
4 
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4 
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2 8 
 1
8 

#include <bits/stdc++.h>
using namespace std;
template <typename T, typename T1>
ostream &operator<<(ostream &out, pair<T, T1> obj) {
  out << "(" << obj.first << "," << obj.second << ")";
  return out;
}
template <typename T, typename T1>
ostream &operator<<(ostream &out, map<T, T1> cont) {
  typename map<T, T1>::const_iterator itr = cont.begin();
  typename map<T, T1>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
  return out;
}
template <typename T>
ostream &operator<<(ostream &out, set<T> cont) {
  typename set<T>::const_iterator itr = cont.begin();
  typename set<T>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
  return out;
}
template <typename T>
ostream &operator<<(ostream &out, multiset<T> cont) {
  typename multiset<T>::const_iterator itr = cont.begin();
  typename multiset<T>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
  return out;
}
template <typename T,
          template <typename ELEM, typename ALLOC = allocator<ELEM>> class CONT>
ostream &operator<<(ostream &out, CONT<T> cont) {
  typename CONT<T>::const_iterator itr = cont.begin();
  typename CONT<T>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
  return out;
}
template <typename T, unsigned int N, typename CTy, typename CTr>
typename enable_if<!is_same<T, char>::value, basic_ostream<CTy, CTr> &>::type
operator<<(basic_ostream<CTy, CTr> &out, const T (&arr)[N]) {
  for (auto i = 0; i < N; ++i) out << arr[i] << " ";
  out << endl;
  return out;
}
template <typename T>
T gcd(T a, T b) {
  T min_v = min(a, b);
  T max_v = max(a, b);
  while (min_v) {
    T temp = max_v % min_v;
    max_v = min_v;
    min_v = temp;
  }
  return max_v;
}
template <typename T>
T lcm(T a, T b) {
  return (a * b) / gcd(a, b);
}
template <typename T>
T fast_exp_pow(T base, T exp, T mod) {
  T res = 1;
  while (exp) {
    if (exp & 1) {
      res *= base;
      res %= mod;
    }
    exp >>= 1;
    base *= base;
    base %= mod;
  }
  return res % mod;
}
int N, M, X, Y;
int Parent[200010], Rank[200010], counts[200010];
set<int> non_neigh[200010];
vector<int> leaders, leaders_count;
int Find(int node) {
  return Parent[node] = (Parent[node] != node ? Find(Parent[node]) : node);
}
void Union(int nde_1, int nde_2) {
  if (Rank[nde_1] >= Rank[nde_2]) {
    Parent[nde_2] = nde_1;
    Rank[nde_1] += Rank[nde_2];
  } else {
    Parent[nde_1] = nde_2;
    Rank[nde_2] += Rank[nde_1];
  }
}
int main() {
  scanf("%d%d", &N, &M);
  for (auto i = 0; i < M; ++i) {
    scanf("%d%d", &X, &Y);
    non_neigh[X].insert(Y);
    non_neigh[Y].insert(X);
  }
  for (auto i = 1; i <= N; ++i) {
    non_neigh[i].insert(i);
    Parent[i] = i;
    Rank[i] = 1;
  }
  for (auto i = 1; i <= N; ++i) {
    int node = 1;
    auto itr = non_neigh[i].begin();
    for (auto t = 1; t <= 2; ++t) {
      while (itr != non_neigh[i].end() && node == *itr) {
        ++node, ++itr;
      }
      if (node > N) {
        continue;
      }
      non_neigh[node].insert(i);
      int par_1 = Find(i);
      int par_2 = Find(node);
      if (par_1 != par_2) {
        Union(par_1, par_2);
      }
      ++node;
    }
  }
  int comp = 0;
  for (auto i = 1; i <= N; ++i) {
    int par = Find(i);
    if (par == i) {
      leaders.push_back(i);
    }
    ++counts[par];
  }
  printf("%d\n", (int)leaders.size());
  for (auto elem : leaders) {
    leaders_count.push_back(counts[elem]);
  }
  sort(leaders_count.begin(), leaders_count.end());
  for (auto elem : leaders_count) {
    printf("%d ", elem);
  }
  printf("\n");
  return 0;
}
