#include <bits/stdc++.h>   using namespace std;   bool changed[222222];   pair<int, int> edges[222222];   set<pair<int, int> > adj[111111];   bool visited[111111];   deque<pair<int, int> > to_connect;   vector<int> Harry;   char outbuf[12000000];   char* out = outbuf;   int moves = 0;   void flush_harry() {     out += sprintf(out,  %d , Harry.size());     for (int v : Harry) {       out += sprintf(out,   %d , v);     }     out += sprintf(out,   n );     Harry.clear();   }   void move_stairs(int id, int u, int v) {     ++moves;     flush_harry();     adj[edges[id].first].erase(pair<int, int>(edges[id].second, id));     adj[edges[id].second].erase(pair<int, int>(edges[id].first, id));     edges[id].first = u, edges[id].second = v;     adj[u].insert(pair<int, int>(v, id));     adj[v].insert(pair<int, int>(u, id));     out += sprintf(out,  %d %d %d n , id, u, v);     changed[id] = true;   }   vector<int> in_component;   bool dfs1(int v, int parent_edge, bool connected_to_one) {     visited[v] = true;     in_component.push_back(v);     int edge_to_move = -1;     for (auto& p : adj[v]) {       if (!connected_to_one && visited[p.first] && parent_edge != p.second) {         edge_to_move = p.second;         connected_to_one = true;       } else if (!visited[p.first]) {         connected_to_one = dfs1(p.first, p.second, connected_to_one);       }     }     if (edge_to_move != -1) {       move_stairs(edge_to_move, v, 1);     }     return connected_to_one;   }   void dfs2(int v, int parent_edge) {     if (v != 1) Harry.push_back(v);     visited[v] = true;     for (auto& p : adj[v])       if (!visited[p.first]) {         dfs2(p.first, p.second);         Harry.push_back(v);       }     vector<pair<int, int> > to_change;     for (auto& p : adj[v])       if (p.second != parent_edge && !to_connect.empty() && !changed[p.second]) {         to_change.push_back(pair<int, int>(p.second, to_connect.back().second));         to_connect.pop_back();       }     for (auto& p : to_change) {       move_stairs(p.first, v, p.second);       dfs2(p.second, p.first);       Harry.push_back(v);     }   }   int main() {     int N, M;     scanf( %d%d , &N, &M);     for (int i = (0); i < (M); ++i) {       int a, b;       scanf( %d%d , &a, &b);       adj[a].insert(pair<int, int>(b, i + 1));       adj[b].insert(pair<int, int>(a, i + 1));       edges[i + 1].first = a, edges[i + 1].second = b;     }     Harry.push_back(1);     for (int i = (1); i < (N + 1); ++i)       if (!visited[i]) {         bool connected_to_one = dfs1(i, -1, i == 1);         if (!connected_to_one) {           for (int& v : in_component)             if (adj[v].size() <= 1) {               to_connect.push_back(pair<int, int>(in_component.size(), v));               break;             }         }         in_component.clear();       }     sort(to_connect.begin(), to_connect.end());     for (int i = (1); i < (N + 1); ++i) visited[i] = false;     dfs2(1, -1);     while (!to_connect.empty() && to_connect.back().first > 1) {       int v = to_connect.back().second;       to_connect.push_front(pair<int, int>(1, v));       to_connect.pop_back();       pair<int, int> n = *adj[v].begin();       move_stairs(n.second, 1, n.first);       dfs2(n.first, n.second);       Harry.push_back(1);     }     flush_harry();     if (!to_connect.empty()) {       printf( NO n );       return 0;     }     printf( YES n%d n , moves);     printf( %s n , outbuf);   }   