#include<iostream>             //广度优先遍历

int main() {
	int i,j,n,m, a, b, cur,book[101]= {0},e[101][101];
	int que[10001],head,tail;
	scanf("%d %d",&n,&m);

	//初始化二维矩阵
	for (i = 1; i <= m; ++i) {
		for (int j = 1; j <= n; ++j) {
			if (i == j)
				e[i][j] = 0;
			else
				e[i][j] = 99999999;   //假设99999999为正无穷
		}
	}
	//读入顶点之间的边
	for (i = 1; i <= m; ++i) {   //读入顶点间的边
		scanf("%d %d",&a,&b);
		e[a][b] = 1;
		e[b][a] = 1;	//因为是无向图
	}
	//队列初始化
	head=1;
	tail=1;
	//从1号顶点出发,将1号顶点加入队列
	que[tail]=1;
	tail++;
	book[1]=1;
	//当队列不为空的时候循环
	while (head<tail && tail<=n) {
		cur=que[head];
		for (i = 1; i <= n; ++i) {
			if (e[cur][i] == 1 && book[i] == 0) {
				que[tail]=i;
				tail++;
				book[i] = 1;
			}
			if(tail>n) {
				break;
			}
		}
		head++;
	}
	for(i=1;i<tail;i++)
		printf("%d",que[i]);
	getchar();
	getchar();
	return 0;
}