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;
enum color_t { White, Black, Gray };
inline int readInt() {
  char c;
  while (c = getchar(), c != '-' && (c < '0' || c > '9'))
    ;
  bool sign = (c == '-');
  if (sign) c = getchar();
  int n = c - '0';
  while (c = getchar(), c >= '0' && c <= '9') n = 10 * n + c - '0';
  return (!sign) ? n : -n;
}
inline long long readLong() {
  char c;
  while (c = getchar(), c != '-' && (c < '0' || c > '9'))
    ;
  bool sign = (c == '-');
  if (sign) c = getchar();
  long long n = c - '0';
  while (c = getchar(), c >= '0' && c <= '9') n = 10 * n + c - '0';
  return (!sign) ? n : -n;
}
inline void getInt(int &n) {
  char c;
  while (c = getchar(), c != '-' && (c < '0' || c > '9'))
    ;
  bool sign = (c == '-');
  if (sign) c = getchar();
  n = c - '0';
  while (c = getchar(), c >= '0' && c <= '9') n = 10 * n + c - '0';
  if (sign) n = -n;
}
inline void getLong(long long &n) {
  char c;
  while (c = getchar(), c != '-' && (c < '0' || c > '9'))
    ;
  bool sign = (c == '-');
  if (sign) c = getchar();
  n = c - '0';
  while (c = getchar(), c >= '0' && c <= '9') n = 10 * n + c - '0';
  if (sign) n = -n;
}
inline string readString() {
  char c;
  while (c = getchar(), c == ' ' || c == '\n' || c == '\t')
    ;
  string s({c});
  while (c = getchar(), c != ' ' && c != '\n' && c != '\t') s += c;
  return s;
}
char bufWrite[20];
template <typename T>
inline void writeInt(T x) {
  if (x < 0) putchar('-'), x = -x;
  char *bufPos = bufWrite;
  do {
    *bufPos++ = x % 10 + '0';
  } while (x /= 10);
  do {
    putchar(*--bufPos);
  } while (bufPos > bufWrite);
}
template <typename T>
inline void printInt(T x, char c = EOF) {
  if (x < 0) putchar('-'), x = -x;
  char *bufPos = bufWrite;
  do {
    *bufPos++ = x % 10 + '0';
  } while (x /= 10);
  do {
    putchar(*--bufPos);
  } while (bufPos > bufWrite);
  if (c != EOF) putchar(c);
}
template <typename T>
inline T gcd(T a, T b) {
  while (b != 0) swap(b, a %= b);
  return a;
}
template <typename T>
inline T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <typename T>
inline tuple<T, T, T> extgcd(T a, T b) {
  if (!a) return make_tuple(b, 0, 1);
  T g, x, y;
  tie(g, x, y) = extgcd(b % a, a);
  return make_tuple(g, (y - (b / a) * x), x);
}
template <class T>
T bitGet(T x, int bit) {
  return T(1) & (x >> (bit - 1));
}
template <class T>
void bitSet(T &x, int bit) {
  x |= (T(1) << (bit - 1));
}
template <class T>
void bitReset(T &x, int bit) {
  x &= ~(T(1) << (bit - 1));
}
template <class T>
void bitFlip(T &x, int bit) {
  x ^= (T(1) << (bit - 1));
}
template <class T>
void bitMake(T &x, int bit, bool val) {
  x ^= (T(1) << (bit - 1)) & (-val ^ x);
}
int n, m;
vector<pair<int, int> > EG;
vector<vector<bool> > MG;
vector<vector<int> > UG;
vector<vector<pair<int, int> > > G;
vector<set<int> > PG;
vector<bool> mark;
vector<color_t> color;
vector<int> dep, deg, par;
vector<int> lvl, cap, ori;
inline void DSU_make(int u) {
  ori[u] = -1;
  cap[u] = 1;
  lvl[u] = 1;
}
inline int DSU_find(int u) {
  return ori[u] < 0 ? u : (ori[u] = DSU_find(ori[u]));
}
inline void DSU_union(int u, int v) {
  if (u = DSU_find(u), v = DSU_find(v); u == v) return;
  if (lvl[u] < lvl[v]) swap(u, v);
  ori[v] = u;
  cap[u] += cap[v];
  lvl[u] += (lvl[u] == lvl[v]);
}
int collect = 0;
void dfs(int u) {
  mark[u] = true;
  collect++;
  int pre = 0;
  for (set<int>::iterator it = PG[u].begin(); it != PG[u].end(); ++it) {
    for (int v = pre + 1; v < *it; ++v)
      if (!mark[v]) dfs(v);
    pre = *it;
  }
  for (int v = pre + 1; v <= n; ++v)
    if (!mark[v]) dfs(v);
}
int readGraph() {
  n = readInt();
  m = readInt();
  PG.resize(n + 1);
  mark.assign(n + 1, false);
  for (int i = 0; i < m; ++i) {
    int u = readInt();
    int v = readInt();
    PG[u].insert(v);
    PG[v].insert(u);
  }
  return 0;
}
int main() {
  readGraph();
  vector<int> res;
  for (int i = 1; i <= n; ++i) {
    if (!mark[i]) {
      collect = 0;
      dfs(i);
      res.push_back(collect);
    }
  }
  cout << res.size() << '\n';
  for (const int x : res) cout << x << ' ';
  return 0;
}
