#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;

int N, M;
vector <int> v[100];
int start;

void input()
{
    scanf("%d %d", &N, &M);
    int a, b;
    for( int i = 0; i < M; i++ )
    {
        scanf("%d %d", &a, &b);
        v[a-1].push_back(b-1);
        v[b-1].push_back(a-1);
    }
    scanf("%d", &start);
    start--;
}

bool used[100];
void bfs()
{
    queue <int> q;
    vector <int> vertices;
    cout << "#0: " << start+1 << endl;
    q.push(start);
    used[start] = 1;
    int br1 = 1, br2 = 0;
    int level = 1;

    while( !q.empty() )
    {
        int tmp = q.front();
        q.pop();
        br1--;

        for( int i = 0; i < v[tmp].size(); i++ )
            if( !used[v[tmp][i]] )
            {
                used[v[tmp][i]] = 1;
                q.push(v[tmp][i]);
                vertices.push_back(v[tmp][i]);
                br2++;
            }
        if( br1 == 0 && br2 )
        {
            br1 = br2;
            br2 = 0;
            cout << "#" << level << ": ";
            for( int i = 0 ; i < vertices.size(); i++ )
                cout << vertices[i]+1 << " ";
            cout << endl;
            vertices.clear();
            level++;
        }
    }
    cout << endl;
}

int main()
{
    input();
    bfs();

    return 0;
}
/**
8 9
1 3
1 9
1 2
2 8
2 5
2 10
10 9
5 7
7 10
1
**/