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#include <stdio.h>
#include <set>
#include <vector>
#include <algorithm>

int anyFromSet(std::set<int> &theSet) {
    int anyValue = *theSet.begin();
    theSet.erase(anyValue);
    return anyValue;
}

bool contains(std::set<int> &theSet, int value) {
    return theSet.find(value) != theSet.end();
}

std::vector<int> getAnyConnectedComponent(std::vector<std::set<int>> &nodes, std::set<int> &unvisitedNodes) {
    std::set<int> nodesToCheck;
    std::vector<int> connectedComponent;
    int firstNode = anyFromSet(unvisitedNodes);
    connectedComponent.push_back(firstNode);

    for(auto node : nodes[firstNode]) {
        nodesToCheck.insert(node);
        unvisitedNodes.erase(node);
        connectedComponent.push_back(node);
    }

    while (!nodesToCheck.empty()){
        int currentCheckedNode = anyFromSet(nodesToCheck);

        for(auto node : nodes[currentCheckedNode]) {
            if(contains(unvisitedNodes, node)){
                nodesToCheck.insert(node);
                unvisitedNodes.erase(node);
                connectedComponent.push_back(node);
            }
        }
    }

    return connectedComponent;
}

void connectedComponents(std::vector<std::set<int>> &nodes) {
    std::set<int> nodesToCheck;

    for(int node = 1 ; node < nodes.size() ; ++node) {
        if(nodes[node].size() > 0) {
            nodesToCheck.insert(node);
        }
    }

    std::vector<int> longest;

    while(!nodesToCheck.empty()) {
        std::vector<int> component = getAnyConnectedComponent(nodes, nodesToCheck);
        if(component.size() > longest.size()) {
            longest = component;
        }
    }

    std::sort(longest.begin(), longest.end());

    printf("%d\n", longest.size());
    for(auto node: longest) {
        printf("%d ", node);
    }
}

int main() {
    int n, m, d;
    scanf("%d %d %d", &n, &m, &d);
    std::vector<std::set<int>> nodes(n+1);
    
    for(int i = 0 ; i < m ; ++i) {
        int first, second;
        scanf("%d %d", &first, &second);
        
        nodes[first].insert(second);
        nodes[second].insert(first);
    }
    
    std::set<int> nodesToCheck;
    
    for(int i = 1 ; i <= n ; ++i) {
        if(nodes[i].size() < d) {
            nodesToCheck.insert(i);
        }
    }
    
    while(!nodesToCheck.empty()) {
        int nodeToCheck = *nodesToCheck.begin();
        
        for(auto vertex : nodes[nodeToCheck]) {
            nodes[vertex].erase(nodeToCheck);
            if(nodes[vertex].size() < d) {
                nodesToCheck.insert(vertex);
            }
        }
        
        nodes[nodeToCheck].clear();
        nodesToCheck.erase(nodeToCheck);
    }
    
    bool found = false;
    for(int i = 1 ; i <= n ; ++i) {
        if(nodes[i].size() >= d) {
            found = true;
        }
    }
    
    if(!found) {
        printf("NIE\n");
        return 0;
    }

    connectedComponents(nodes);

    return 0;
}