#include <stdio.h>
int main()
{
    int i, j, m, a, b, cur,n, book[101] = { 0 }, e[101][101];
    int que[10001], head, tail;
    scanf("%d %d", &n, &m);
    //初始化二維矩陣
    for (i = 1; i <= n; i++)
        for (j = 1; j <= n; j++)
            if (i == j) e[i][j] = 0;
            else e[i][j] = 99999999;	//我們假設99999999為x
 
    //讀入頂點之間的邊
    for (i = 1; i <= n; i++)
    {
        scanf("%d %d", &a, &b);
        e[a][b] = 1;
        e[b][a] = 1;	//因為該圖為無向圖
    }
 
    //隊列初始化
    head = 1;
    tail = 1;
 
    //從1號頂點出發(fā)，將1號頂點加入隊列
    que[tail] = 1;
    tail++;
    book[1] = 1;//標記1號頂點已經(jīng)入列
 
    //當隊列不為空時循環(huán)
    while (head < tail && tail <= n)
    {
        cur = que[head];  //當前正在訪問的頂點編號
        for (i = 1; i <= n; i++)
        {
            //判斷從頂點cur到頂點i是否有邊，并判斷頂點i是否訪問過
            if (e[cur][i] == 1 && book[i] == 0)
            {
                //如果從頂點cur到頂點i右邊，且頂點i沒有被訪問過，將頂點i入列
                que[tail] = i;
                tail++;
                book[i] = 1; //標記表示已經(jīng)訪問過
 
            }
            if (tail > n)  //表示所有點都已經(jīng)訪問過
                break;
        }
 
        head++;
        //注意這個地方，不要忘記head++后，才能繼續(xù)向下拓展
    }
 
    for (i = 1; i < tail; i++)
        printf("%d",que[i]);
 
 
}