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import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.LinkedList;

public class mis {
  public static void main(String... args) throws IOException {
    FastScanner scanner = new FastScanner(System.in);

    int numberOfCities = scanner.nextInt();
    int numberOfRoads = scanner.nextInt();
    int requiredNumberOfRoads = scanner.nextInt();

    LinkedList<Integer>[] roadsFrom = new LinkedList[numberOfCities + 1];
    for (int city = 1; city <= numberOfCities; city++) {
      roadsFrom[city] = new LinkedList<>();
    }

    for (int road = 0; road < numberOfRoads; road++) {
      int cityA = scanner.nextInt();
      int cityB = scanner.nextInt();
      roadsFrom[cityA].add(cityB);
      roadsFrom[cityB].add(cityA);
    }

    int[] numberOfRoadsFrom = new int[numberOfCities + 1];
    for (int city = 1; city <= numberOfCities; city++) {
      numberOfRoadsFrom[city] = roadsFrom[city].size();
    }

    LinkedList<Integer> suspects = new LinkedList<>();
    for (int city = 1; city <= numberOfCities; city++) {
      suspects.add(city);
    }
    while (!suspects.isEmpty()) {
      int cityA = suspects.removeFirst();
      if (0 < numberOfRoadsFrom[cityA] && numberOfRoadsFrom[cityA] < requiredNumberOfRoads) {
        numberOfRoadsFrom[cityA] = 0;
        for (int cityB : roadsFrom[cityA]) {
          numberOfRoadsFrom[cityB]--;
          suspects.add(cityB);
        }
      }
    }

    boolean[] isCandidate = new boolean[numberOfCities + 1];
    for (int city = 1; city <= numberOfCities; city++) {
      if (numberOfRoadsFrom[city] >= requiredNumberOfRoads) {
        isCandidate[city] = true;
      }
    }

    for (int cityA = 1; cityA <= numberOfCities; cityA++) {
      if (numberOfRoadsFrom[cityA] < requiredNumberOfRoads) {
        roadsFrom[cityA].clear();
      } else {
        LinkedList<Integer> filtered = new LinkedList<>();
        for (int cityB : roadsFrom[cityA]) {
          if (isCandidate[cityB]) {
            filtered.add(cityB);
          }
        }
        roadsFrom[cityA] = filtered;
      }
    }

    LinkedList<Integer> best = new LinkedList<>();

    for (int seed = 1; seed < numberOfCities; seed++) {
      if (!isCandidate[seed]) {
        continue;
      }
      LinkedList<Integer> reachableCities = new LinkedList<>();
      LinkedList<Integer> reachedCities = new LinkedList<>();

      isCandidate[seed] = false;
      reachableCities.add(seed);
      while (!reachableCities.isEmpty()) {
        int reachingCity = reachableCities.removeFirst();
        reachedCities.add(reachingCity);

        for (Integer targetCity : roadsFrom[reachingCity]) {
          if (isCandidate[targetCity]) {
            reachableCities.add(targetCity);
            isCandidate[targetCity] = false;
          }
        }
      }
      if (reachedCities.size() > best.size()) {
        best = reachedCities;
      }
    }

    FastPrinter printer = new FastPrinter(System.out);
    if (best.size() > 0) {
      printer.printLine(best.size());
      Object[] array = best.toArray();
      Arrays.sort(array);
      printer.printLine(array);
    } else {
      printer.printLine("NIE");
    }
    printer.close();
  }

  private static class FastScanner {
    private final InputStream stream;
    private final byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;

    public FastScanner(InputStream stream) {
      this.stream = stream;
    }

    public int read() {
      if (numChars == -1) {
        throw new InputMismatchException();
      }
      if (curChar >= numChars) {
        curChar = 0;
        try {
          numChars = stream.read(buf);
        } catch (IOException e) {
          throw new InputMismatchException();
        }
        if (numChars <= 0) {
          return -1;
        }
      }
      return buf[curChar++];
    }

    public int nextInt() {
      int c = read();
      while (isSpaceChar(c)) {
        c = read();
      }
      int sgn = 1;
      if (c == '-') {
        sgn = -1;
        c = read();
      }
      int res = 0;
      do {
        if (c < '0' || c > '9') {
          throw new InputMismatchException();
        }
        res *= 10;
        res += c - '0';
        c = read();
      } while (!isSpaceChar(c));
      return res * sgn;
    }

    public boolean isSpaceChar(int c) {
      if (filter != null) {
        return filter.isSpaceChar(c);
      }
      return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    public interface SpaceCharFilter {
      public boolean isSpaceChar(int ch);
    }
  }

  private static class FastPrinter {
    private final PrintWriter writer;

    public FastPrinter(OutputStream outputStream) {
      writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }

    public void print(Object... objects) {
      for (int i = 0; i < objects.length; i++) {
        if (i != 0) {
          writer.print(' ');
        }
        writer.print(objects[i]);
      }
    }

    public void printLine(Object... objects) {
      print(objects);
      writer.println();
    }

    public void close() {
      writer.close();
    }
  }
}