#include <iostream>
#include <vector>
using namespace std ;
const int MAXN = 1000 ;
vector<vector<pair<int,int>>> edges, oedges ;
int adj[MAXN][MAXN], oadj[MAXN][MAXN] ;
     // 0 means this edge is deleted or never existed
char aspec[MAXN][MAXN] ;
vector<char> visited, ndel, ondel ;
vector<int> tin, low, live, olive, isspec ;
int n, m, k ;
int timer ;
void rmedge(int a, int b) {
   if (adj[a][b] == 0)
      return ;
   adj[a][b] = adj[b][a] = 0 ;
}
void rmnode(int a) {
   if (ndel[a])
      return ;
   ndel[a] = 1 ;
   for (auto b: edges[a]) {
      rmedge(a, b.first) ;
      if (b.second)
         rmnode(b.first) ;
   }
}
void dfs(int v, int p = -1) {
   visited[v] = true ;
   if (ndel[v])
      return;
   tin[v] = low[v] = timer++ ;
   for (auto b: edges[v]) {
      int to = b.first ;
      if (ndel[to] || adj[v][to] == 0 || to == p) continue ;
      if (visited[to]) {
         low[v] = min(low[v], tin[to]) ;
      } else {
         dfs(to, v) ;
         low[v] = min(low[v], low[to]) ;
         if (low[to] > tin[v])
            adj[v][to] = adj[to][v] = -1 ;
      }
   }
}
void find_bridges() {
   timer = 0 ;
   visited.assign(n, false) ;
   tin.assign(n, -1) ;
   low.assign(n, -1) ;
   for (int i=0; i<n; i++)
      if (!visited[i])
         dfs(i) ;
}
void restore() {
   edges = oedges ;
   ndel = ondel ;
   live = olive ;
   for (int i=0; i<n; i++)
      for (int j=0; j<n; j++)
         adj[i][j] = oadj[i][j] ;
}
void save() {
   oedges = edges ;
   ondel = ndel ;
   olive = live ;
   for (int i=0; i<n; i++)
      for (int j=0; j<n; j++)
         oadj[i][j] = adj[i][j] ;
}
void rmedge2(int a, int b) {
   rmedge(a, b) ;
   if (aspec[a][b]) {
      rmnode(a) ;
      rmnode(b) ;
   }
}
int clean() {
   while (1) {
      int changed = 0 ;
      find_bridges() ;
      for (int a=0; a<n; a++)
         for (auto b: edges[a])
            if (adj[a][b.first] < 0) {
               rmedge2(a, b.first) ;
               changed = 1 ;
            }
      if (!changed)
         break ;
   }
   for (int a=0; a<n; a++) {
      vector<pair<int, int>> ne ;
      for (auto b: edges[a])
         if (adj[a][b.first])
            ne.push_back(b) ;
      swap(edges[a], ne) ;
   }
   live.clear() ;
   for (int a=0; a<n; a++)
      if (!ndel[a] && edges[a].size() > 1)
         live.push_back(a) ;
   return live.size() ;
}
int main() {
   cin >> n >> m >> k ;
   isspec.resize(n) ;
   edges.resize(n) ;
   visited.resize(n) ;
   tin.resize(n) ;
   low.resize(n) ;
   for (int i=0; i<m; i++) {
      int a, b ;
      cin >> a >> b ;
      int s = (i < k) ;
      a-- ;
      b-- ;
      edges[a].push_back({b,s}) ;
      edges[b].push_back({a,s}) ;
      adj[a][b] = adj[b][a] = 1 ;
      if (s) {
         isspec[a]++ ;
         isspec[b]++ ;
         aspec[a][b] = aspec[b][a] = 1 ;
      }
   }
   ndel.resize(n) ;
   for (int a=0; a<n; a++)
      if (isspec[a] > 2)
         rmnode(a) ;
   for (int a=0; a<n; a++)
      if (isspec[a] == 2)
         for (auto b: edges[a])
            if (b.second == 0)
               rmedge(a, b.first) ;
   if (clean() == 0) {
      cout << -1 << endl ;
      exit(0) ;
   }
   while (1) {
      int changed = 0 ;
      for (int i=0; i<n; i++)
         for (int j=i+1; j<n; j++)
            if (adj[i][j] == 1) {
               save() ;
               rmedge2(i, j) ;
               if (clean() == 0) {
                  restore() ;
               } else {
                  changed++ ;
               }
            }
      if (changed == 0)
         break ;
   }
   cout << live.size() << endl ;
   int a = live[0] ;
   int b = edges[a][0].first ;
   visited[a] = 2 ;
   visited[b] = 2 ;
   vector<int> sol ;
   sol.push_back(a) ;
   sol.push_back(b) ;
   while (1) {
      int c = -1 ;
      for (int i=0; i<(int)edges[b].size(); i++)
         if (visited[edges[b][i].first] != 2)
            c = edges[b][i].first ;
      if (c < 0)
         break ;
      sol.push_back(c) ;
      visited[c] = 2 ;
      a = b ;
      b = c ;
   }
   for (auto a: sol)
      cout << " " << 1+a ;
   cout << endl ;
}