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#include <cstdio>
#include <set>

const int MAXN = 200010;
std::set< int > v[MAXN];
int parent[MAXN];
int sizeOfSet[MAXN];

int getParent(int i) {
  if(parent[i] < 0) {
    return i;
  } else {
    parent[i] = getParent(parent[i]);
    return parent[i];
  }
}

int mergeSets(int a, int b) {
  //printf("merging %d and %d\n", a, b);

  int pa = getParent(a);
  int pb = getParent(b);

  //printf("\tpa, pb: %d, %d\n", pa, pb);

  if(pa != pb) {
    if(-parent[pa] < -parent[pb]) {
      parent[pa] = pb;
      sizeOfSet[pb] += sizeOfSet[pa];
      return sizeOfSet[pb];
    } else {
      if(-parent[pa] == -parent[pb]) {
        parent[pa]--;
      }
      parent[pb] = pa;
      //printf("\tparent[%d]: %d\n", pb, parent[pb]);
      sizeOfSet[pa] += sizeOfSet[pb];
      return sizeOfSet[pa];
    }
  } else {
    return sizeOfSet[pa];
  }
}

int main() {
  int n, m, d;
  scanf("%d%d%d", &n, &m, &d);
  for(int e = 0; e < m; e++) {
    int a, b;
    scanf("%d%d", &a, &b);
    v[a].insert(b);
    v[b].insert(a);
  }

  //printf("Creating toRemove.\n"); fflush(stdout);
  std::set< int > toRemove;
  for(int i = 1; i <= n; i++) {
    parent[i] = -1;
    sizeOfSet[i] = 1;
    if(v[i].size() < d) {
      toRemove.insert(i);
      //printf("toRemove.insert(%d)\n", i); fflush(stdout);
    }
  }
  //printf("Created toRemove.\n\n"); fflush(stdout);

  std::set< int > removed;
  while(!toRemove.empty()) {
    int i = *toRemove.begin();
    toRemove.erase(i);
    removed.insert(i);
    //printf("Removing vertex %d\n", i); fflush(stdout);
    for(std::set< int >::iterator it = v[i].begin(); it != v[i].end(); it++) {
      if(removed.find(*it) == removed.end()) {
        v[*it].erase(i);
        //printf("Removing edge %d-%d\n", *it, i); fflush(stdout);
        if(v[*it].size() < d) {
          toRemove.insert(*it);
          //printf("toRemove.insert(%d)\n", *it); fflush(stdout);
        }
      }
    }
  }

  int largestSetSize = 0;
  int largestSetInd = -1;
  for(int i = 1; i <= n; i++) {
    if(removed.find(i) == removed.end()) {
      for(std::set< int >::iterator it = v[i].begin(); it != v[i].end(); it++) {
        int sizeOfCurrSet = mergeSets(i, *it);
        if(sizeOfCurrSet > largestSetSize) {
          largestSetSize = sizeOfCurrSet;
          //printf("largestSetSize = %d\n", largestSetSize);
          largestSetInd = getParent(i);
        }
      }
    }
  }

  if(largestSetSize == 0) {
    printf("NIE\n");
  } else {
    printf("%d\n", largestSetSize);
    for(int i = 1; i <=n; i++) {
      if(getParent(i) == largestSetInd) {
        printf("%d ", i);
      }
    }
    printf("\n");
  }

  return 0;
}