找环2

7 5
1 2 3 4 4 5 6 7 7 6
5 5
1 2 2 3 3 4 4 5 3 1
4 3
1 2 3 2 4 3
3 3
8 4 4 6 6 8
9 37
1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 4 3 5 3 6 3 7 3 8 3 9 4 5 4 6 4 7 4 8 4 9 5 6 5 7 5 8 5 9 6 7 6 8 6 9 7 8 7 9 8 9 9 3
9 8
1 2 2 3 3 4 4 6 5 6 6 7 7 8 8 9
4 3
1 2 2 3 3 4
5 5
1 2 1 3 2 4 2 5 5 4
0 0

//不对

#include<stdio.h>
#include<stdlib.h>
int shu,bian;
int data[10000][2];
struct ueue{
	int x;
	int y;
	int pre_node;
}q;
ueue queue[10000];
int head,tail;
void BFS();
int main()
{
	freopen("a.txt","r",stdin);
	while(1)
	{
		scanf("%d",&shu);
		scanf("%d",&bian);
		if(shu == 0 || bian == 0)
		{
			return 0;
		}
		for(int i = 0;i < bian;i++)
		{
			scanf("%d",&data[i][0]);
			scanf("%d",&data[i][1]);
		}
		BFS();
		for(int i = 0;i < bian;i++)
		{
			data[i][0] = 0;
			data[i][1] = 0;
		}
		for(int k = 0;k < tail;k++)
		{
			q.x = 0;
			q.y = 0;
			q.pre_node = 0;
			queue[k] = q;
		}
		tail = 0;
		head = 0;
	}
	return 0;

}
void BFS()
{
	for(int o = 0;o < bian;o++)
	{
		if(data[o][0] != 0 && data[o][1] != 0)
		{
			int t = 0;
			q.x = data[o][0];
			q.y = data[o][1];
			queue[tail] = q;
			tail += 1;
			data[o][0] = 0;
			data[o][1] = 0;
			while(head != tail)
			{
				for(int i = 1;i < bian;i++)
				{
					if(data[i][0] == queue[head].y)
					{
						q.x = data[i][0];
						q.y = data[i][1];
						q.pre_node = head;
						queue[tail] = q;
						tail++;
						data[i][0] = 0;
						data[i][1] = 0;
					}
				}
				head++;
			}
			for(int p = o;p < tail;p++)
			{
				for(int q = p + 1;q <= tail;q++)
				{
					if(queue[p].x == queue[q].y)
					{
						printf("%d",queue[q].x);
						t = queue[q].pre_node;
						while(1)
						{
							printf("%d",queue[t].x);
							if(queue[t].x == queue[p].x)
							{
								printf("\n");
								break;
							}
							t = queue[t].pre_node;
						}
						return;
					}
				}
			}
		}
	}
	printf("no\n");
}




//DFS yes
#include<stdio.h>
#include<stdlib.h>
int shu,bian;
int data[10000][2];
int dfs[10][10] = {0};
int cun[10] = {0};
int c[10];
int n;
bool ret = false;
void DFS(int step,int x);
int main()
{
	freopen("a.txt","r",stdin);
	while(1)
	{
		scanf("%d",&shu);
		scanf("%d",&bian);
		if(shu == 0 || bian == 0)
		{
			return 0;
		}
		for(int i = 0;i < bian;i++)
		{
			ret = false;
			scanf("%d",&data[i][0]);
			scanf("%d",&data[i][1]);
			dfs[data[i][0]][data[i][1]] = 1;
		}

		/*for(int i = 1;i < 10;i++)
		{
			for(int j = 1;j < 10;j++)
			{
				printf("%d ",dfs[i][j]);
			}
			printf("\n");
		}*/
		for(int g = 1;g < 10;g++)
		{
			for(int h = 1;h < 10;h++)
			{
				if(dfs[g][h] == 1)
				{
					DFS(0,g);
					if(ret == true)
					{
						goto v;
					}
				}
			}
		}
		printf("no\n");
		v:for(int i = 1;i < 10;i++)
		{
			for(int j = 1;j < 10;j++)
			{
				dfs[i][j] = 0;
				cun[j] = 0;
				c[j] = 0;
			}
		}
		  n = 0;

	}
	return 0;

}
void DFS(int step,int x)
{
	//if(step == bian)
	//{
	//	return;
	//}
	for(int i = x;i < 10;i++)
	{
		for(int j = 1;j < 10;j++)
		{
			if(dfs[i][j] == 1)
			{
				dfs[i][j] = 2;
				cun[i] = 1;
				c[n] = i;
				n++;
				if(cun[j])
				{
					ret = true;
					for(int k = n - 1;;k--)
					{
							printf("%d ",c[k]);
							if(c[k] == j)
							{
								printf("\n");
								break;
							}
						
					}
					break;
				}
				
				DFS(step + 1,j);
				if(ret)
				{
					break;
				}
				cun[i] = 0;
				n--;
				c[n] = 0;
			}
 		}
		return;
	}
}