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#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

class CoherentSet {
public:
    vector<int> vertices;
    int counter;

    CoherentSet(){
        counter = 0;
    }

    void incrementCounter() {
        counter++;
    }

    void addVertex(int vertexNumber){
        this->vertices.push_back(vertexNumber);
    }

    void printVertices(){
        for(int i=0; i<vertices.size(); i++){
            printf("%d ", vertices[i]+1);
        }
    }
};

class Vertex {
public:
    vector<Vertex*> connections;
    bool active;
    bool visited;
    int activeConnections;
    int id;
    int color;

    Vertex() {
        this->active = true;
        this->activeConnections = 0;
        this->color = 0;
        this->visited = false;
    }

    int getActiveConnections(){
        return this->activeConnections;
    }

    void addActiveConnection(){
        this->activeConnections++;
    }

    void removeActiveConnection(){
        this->activeConnections--;
    }

    void setInactive(){
        this->active = false;
    }

    bool isActive(){
        return this->active;
    }

    int getColor(){
        return this->color;
    }

    void setColor(int color){
        this->color = color;
    }

    bool isVisited() const {
        return visited;
    }

    void setVisited(bool visited) {
        Vertex::visited = visited;
    }
};

int uncolouredCounter = 0;

Vertex* getFirstUncoloredVertex(Vertex *vertices, int verticesNumber){
    for(int i=uncolouredCounter; i<verticesNumber; i++){
        if(vertices[i].getColor() == 0 && vertices[i].isActive()){
            uncolouredCounter = i;
            return &vertices[i];
        }
    }
    return NULL;
}

int main() {
    int verticesNumber = 0;
    int edgesNumber = 0;
    int minimumRoads = 0;
    int fromVertex;
    int toVertex;
    scanf("%d", &verticesNumber);
    scanf("%d", &edgesNumber);
    scanf("%d", &minimumRoads);

    Vertex vertices[verticesNumber];
    for(int i=0; i<verticesNumber; i++){
        vertices[i].id = i;
    }

    for(int i=0; i<edgesNumber; i++){
        scanf("%d", &fromVertex);
        scanf("%d", &toVertex);
        fromVertex--;
        toVertex--;
        vertices[fromVertex].connections.push_back(&vertices[toVertex]);
        vertices[fromVertex].addActiveConnection();
        vertices[toVertex].connections.push_back(&vertices[fromVertex]);
        vertices[toVertex].addActiveConnection();
    }

    queue<Vertex*> bfsQueue;

    // insert all vertices with less than minimumRoads
    for(int i=0; i<verticesNumber; i++){
        if(vertices[i].getActiveConnections() < minimumRoads){
            vertices[i].setInactive();
            bfsQueue.push(&vertices[i]);
        }
    }

    while(bfsQueue.size() != 0) {
        Vertex* current = bfsQueue.front();
        bfsQueue.pop();

        for(int i=0; i<current->connections.size(); i++){
            current->connections[i]->removeActiveConnection();
            if(current->connections[i]->getActiveConnections() < minimumRoads && current->connections[i]->isActive()){
                current->connections[i]->setInactive();
                bfsQueue.push(current->connections[i]);
            }
        }
    }

    int colorCounter = 0;
    int biggestSetId = -1;
    int biggestSetCounter = 0;
    vector<CoherentSet> sets;

    Vertex* firstUncolored = getFirstUncoloredVertex(vertices, verticesNumber);
    while(firstUncolored != NULL){
        CoherentSet set;
        colorCounter++;
        bfsQueue.push(firstUncolored);
        while(bfsQueue.size() != 0) {
            Vertex* current = bfsQueue.front();
            bfsQueue.pop();
            if (current->getColor() != 0) {
                continue;
            }
            set.addVertex(current->id);
            set.incrementCounter();
            current->setColor(colorCounter);
            for (int i = 0; i < current->connections.size(); i++) {
                if(current->connections[i]->isActive() && current->getColor() != 0){
                    bfsQueue.push(current->connections[i]);
                }
            }
        }

        sets.push_back(set);
        if(set.counter > biggestSetCounter){
            biggestSetId = sets.size()-1;
            biggestSetCounter = set.counter;
        }
        firstUncolored = getFirstUncoloredVertex(vertices, verticesNumber);
    }
    if(sets.empty()){
        printf("NIE\n");
    } else {
        printf("%d\n", biggestSetCounter);
        sets[biggestSetId].printVertices();
    }
    return 0;
}