#include<iostream>

#include<vector>

#include<queue>


std::vector<int> a[8];

int c[8] = {0};


/*

a[1].push_back(2);

a[2].push_back(1);

a[1].push_back(3);

a[3].push_back(1);

a[2].push_back(3);

a[3].push_back(2);

a[2].push_back(4);

a[4].push_back(2);

a[2].push_back(5);

a[5].push_back(2);

a[3].push_back(6);

a[6].push_back(3);

a[3].push_back(7);

a[7].push_back(3);

*/


void bfs(int start)

{

std::queue<int> v;

v.push(start);

while(!v.empty())

{

int x = v.front();

c[start] = true;

std::cout<<v.front()<<" ";

v.pop();

for(int i = 0 ; i < a[start].size() ; i++)

{

if(!c[a[start][i]])

{

v.push(a[start][i]);

c[a[start][i]] = 1;

}

}

}

}


int main()

{

a[1].push_back(2);

a[2].push_back(1);

a[1].push_back(3);

a[3].push_back(1);

a[2].push_back(3);

a[3].push_back(2);

a[2].push_back(4);

a[4].push_back(2);

a[2].push_back(5);

a[5].push_back(2);

a[3].push_back(6);

a[6].push_back(3);

a[3].push_back(7);

a[7].push_back(3);

bfs(1);

}


ㅈㄴ 신기하네 ㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋ