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>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

using namespace std;

// #define endl '\n'
#define int long long int
#define rep(i, a, b) for (int i = a; i < b; i++)
#define revrep(i, a, b) for (int i = a; i >= b; i--)
#define pb push_back
#define pii pair<int, int>
#define vi vector<int>
#define vii vector<pii>
#define min3(a, b, c) min(a, min(b, c))
#define max3(a, b, c) max(a, max(b, c))

template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;


ostream &operator<<( ostream &output, const pii &p ) { output << p.first << " " << p.second;return output; }
istream &operator>>( istream &input, pii &p ) { input >> p.first >> p.second;return input; }
template<typename T>
void inline println(vector<T> args){ for(T i: args)cout<<i<<" ";cout<<endl; }
void amax(int& a, int b) { a = max(a, b); }
void amin(int& a, int b) { a = min(a, b); }
int ceilInt(int a, int b) {
    if(!b) return 0;
    if(a%b) return a/b + 1;
    return a/b;
}

int INF = 1e18;
int MOD = 1000000007;


class DSU {
    private:
        vi p, sz;

    public:
        DSU(int n) {
            p.resize(n);
            sz.resize(n, 1);
            rep(i, 0, n) p[i] = i;
        }

        int root(int v) {
            if(v == p[v]) return v;
            return p[v] = root(p[v]);
        }

        void merge(int a, int b) {
            a = root(a), b = root(b);
            if(a == b) return;
            if(sz[a] < sz[b]) swap(a, b);
            sz[a] += sz[b];
            p[b] = a;
        }

        int size(int v) {
            return sz[v];
        }
};


void solve()
{
    int n, m; cin>>n>>m;
    vi ind; ind.resize(n, n-1);
    DSU dsu(n);
    set<pii> edges;
    rep(i, 0, m) {
        int x, y; cin>>x>>y;
        x--, y--;
        edges.insert({min(x, y), max(x, y)});
        ind[x]--;
        ind[y]--;
    }
    vi tog;
    unordered_set<int> les;
    rep(i, 0, n)
        if(ind[i] > n/2) tog.pb(i);
        else les.insert(i);
    rep(i, 0, tog.size()) dsu.merge(tog[0], tog[i]);
    for(int i: les) {
        rep(j, 0, n) {
            if(i == j) continue;
            auto itr = edges.find({min(i, j), max(i, j)});
            if(itr == edges.end()) {
                // cout<<make_pair(i+1, j+1)<<endl;
                dsu.merge(i, j);
            }
        }
    }
    // used.resize(n, false);
    // for(int i: les)
    //     if(!used[i]) dfs(i);
    les.clear();
    rep(i, 0, n) les.insert(dsu.size(dsu.root(i)));
    cout<<les.size()<<endl;
    for(int i: les) cout<<i<<" ";
    cout<<endl;
}



signed main()
{

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
#ifndef ONLINE_JUDGE
    // for getting input from input.txt
    freopen("input.txt", "r", stdin);
    // for writing output to output.txt
    freopen("output.txt", "w", stdout);
#endif

    int t = 1;
    // cin>>t;
    rep(i, 0, t)
    {   
        // cout<<"Case #"<<i+1<<": ";
        solve();
    }
    return 0;
}