#include <iostream>
#include <fstream>
#include <queue>
std::ifstream fin("file.in");

using namespace std;

int graf[15][15], viz[15], n , m;

queue <int> c;

void citire(){
    fin >> n >> m;

    for(int i = 1 ; i <= n; i++){
            int x , y;
            fin >> x >> y;
            graf[x][y] = graf[y][x] = 1;
    }
}

void bfs(int start){

    c.push(start);
    viz[start] = 1;

    int prim = 1, ultim = 1;

    while(prim <= ultim){
        prim++;
        int nod = c.back();

        for(int i = 1; i <= n; i++){
                if(graf[nod][i] && !viz[i]){
                    ultim++;
                    c.push(i);
                    viz[i] = nod;
            }
        }
    }
}


int main(){
    citire();
    bfs(1);

    return 0;
}