#include <bits/stdc++.h>
#define pii pair<int ,int>
#define pb push_back
#define fi first
#define re return
#define se second
#define all(x) x.begin(), x.end()
#define piii pair<pair<int,int>, int>
#define vpii vector<pii>
#define vi vector<int>
#define vpiii vector<piii>
#define musek vector


using namespace std;

typedef long long ll;
typedef long double ld;

const int VERTEX = 20001;

musek<pii> G[VERTEX];
musek<int> used(VERTEX);
musek<int> odd_v;
musek<pii> euler_cycle;
musek<int> was(VERTEX * 2);
musek<int> answer[VERTEX];


void find_euler(int v, int edge) {
    for(auto p: G[v]) {
        int u = p.first;
        int j = p.second;
        if(!was[j]) {
            was[j] = 1;
            find_euler(u, j);
        }
    }
    euler_cycle.pb({v, edge});
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < m; ++i) {
        int v, u;
        cin >> v >> u;
        v--, u--;
        G[v].pb({u, i});
        G[u].pb({v, i});
    }
    for (int i = 0; i < n; ++i) {
        if (G[i].size() % 2 != 0) {
            odd_v.pb(i);
        }
    }
    int c = m;
    for (int i = 0; i < odd_v.size(); i += 2) {
        int v = odd_v[i];
        int u = odd_v[i + 1];
        G[v].pb({u, c});
        G[u].pb({v, c++});
    }
    find_euler(0, -1);
    musek<int> ans;
    int ways = 0;
    reverse(all(euler_cycle));
    for (int i = 0; i < euler_cycle.size(); i++) {
        //cout << euler_cycle[i].fi + 1 << ' ' << euler_cycle[i].se << endl;
        if (i == 0) {
            answer[ways].pb(euler_cycle[0].fi);
            continue;
        }
        auto v = euler_cycle[i - 1];
        auto u = euler_cycle[i];
        if(u.se >= m) {
            ways++;
        }
        answer[ways].push_back(u.fi);
    }
    if(ways == 0) {
        cout << 1 << endl;

        for(int i = 0; i < answer[0].size(); i++) {
            cout << answer[0][i] + 1 << ' ';
        }

        return 0;
    }


    cout << ways << endl;
    for (int i = 1; i < ways; ++i) {
        for(auto x: answer[i]) {
            cout << x + 1 << ' ';
        }
        cout << endl;
    }

    for(int i = 0; i < answer[ways].size() - 1; i++) {
        cout << answer[ways][i] + 1 << ' ';
    }
    for(int i = 0; i < answer[0].size(); i++) {
        cout << answer[0][i] + 1 << ' ';
    }
}