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 INF = int(1e9);
int dx[] = {2, 2, -2, -2, 1, 1, -1, -1};
int dy[] = {-1, 1, 1, -1, 2, -2, 2, -2};
int dxx[] = {1, 0, 0, -1};
int dyy[] = {0, 1, -1, 0};
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
void add(int &a, int b) {
  a += b;
  if (a >= 1000000007) a -= 1000000007;
}
int poww(int x, int y) {
  if (y == 0) return 1;
  if (y == 1) return x;
  return x * poww(x, y - 1);
}
long long int strtoint(string s) {
  int l = s.length();
  long long int temp = 0;
  for (int i = 0; i < l; i++) {
    if (i != l - 1)
      temp = temp + (s[i] - '0') * poww(10, l - i - 1);
    else
      temp = temp + (s[i] - '0');
  }
  return temp;
}
int isprime(long long int x) {
  if (x == 1) return 1;
  if (x == 2) return 1;
  if (x == 3) return 1;
  for (int i = 2; i * i <= x; i++)
    if (x % i == 0) return 0;
  return 1;
}
void cpgod() {}
int lexbig(string s1, string s2) {
  int n1, n2;
  n1 = s1.length();
  n2 = s2.length();
  for (int i = 0; i < n1; i++) {
    if (s1[i] - 'a' > s2[i] - 'a')
      return 1;
    else if (s1[i] - 'a' < s2[i] - 'a')
      return 0;
    else
      continue;
  }
  if (n1 == n2)
    return 1;
  else
    return 0;
}
long long int fast_pow(long long int a, long long int p) {
  long long int res = 1;
  while (p) {
    if (p % 2 == 0) {
      a = a * 1ll * a % 1000000007;
      p /= 2;
    } else {
      res = res * 1ll * a % 1000000007;
      p--;
    }
  }
  return res;
}
long long int lcm(long long int x, long long int y) {
  long long int t = x * y;
  t = t / (gcd(x, y));
  return t;
}
long long int modadd(long long int a, long long int b) {
  a = a % 1000000007;
  b = b % 1000000007;
  return (a + b) % 1000000007;
}
int binaryToDecimal(string n) {
  string num = n;
  int dec_value = 0;
  int base = 1;
  int len = num.length();
  for (int i = len - 1; i >= 0; i--) {
    if (num[i] == '1') dec_value += base;
    base = base * 2;
  }
  return dec_value;
}
long long int ncr(long long int x, long long int y) {
  long long int mul = 1;
  for (int i = x; i > x - y; i--)
    mul = (mul % 1000000007 * i % 1000000007) % 1000000007;
  long long int rem = 1;
  for (int i = 2; i <= y; i++)
    rem = (rem % 1000000007 * i % 1000000007) % 1000000007;
  rem = fast_pow(rem, 1000000007 - 2);
  return (mul % 1000000007 * rem % 1000000007) % 1000000007;
}
vector<set<long long int>> adj(200020);
set<long long int> notused;
int con[200020];
void dfs(int src) {
  notused.erase(src);
  int sear = src;
  while (1) {
    auto ta = notused.upper_bound(sear);
    if (ta == notused.end()) break;
    sear = *ta;
    if (adj[src].find(sear) == adj[src].end()) {
      con[sear] = con[src];
      dfs(sear);
    } else {
      continue;
    }
  }
}
int main() {
  cpgod();
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n, m;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) notused.insert(i);
  long long int a, b;
  for (int i = 0; i < m; i++) {
    cin >> a >> b;
    adj[a].insert(b);
    adj[b].insert(a);
  }
  int sum = 0;
  while (notused.size() != 0) {
    int ta = *(notused.begin());
    con[ta] = ta;
    dfs(ta);
    sum++;
  }
  cout << sum << endl;
  map<int, int> mp;
  for (int i = 1; i <= n; i++) mp[con[i]]++;
  vector<int> va;
  for (auto u : mp) va.push_back(u.second);
  sort(va.begin(), va.end());
  for (auto u : va) cout << u << " ";
  return 0;
}
