#include<bits/stdc++.h>
using namespace std;
int bfs(int,int);
vector<int>adj[100];
int node,edge,i,j;
int vis[100];
int p[100];

int main()
{
    scanf("%d %d",&node,&edge);
    int node1,node2;
    memset(adj,'-1',100);
    for(i=0;i<edge;i++){
        scanf("%d %d",&node1,&node2);
        adj[node1].push_back(node2);
        adj[node2].push_back(node1);
    }
    int start,end;
    scanf("%d %d",&start,&end);
    bfs(start,end);
}

int bfs(int start,int end)
{
    for(i=0;i<node;i++){
        vis[i]=0;
    }
    queue<int> q;
    q.push(start);
    vis[start]=1;
    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        vis[u]=1;
        for(i=0;i<adj[u].size();i++){
            if(vis[adj[u][i]] == 0){
                int v=adj[u][i];
                vis[v]=1;
                p[v]=u;
                q.push(v);
            }
        }
    }
    //cout<<end<<endl;
     if(vis[end]==0){
        return 0;
     }
     else{
        printf("Possible\n");
        vector<int> path;
        path.push_back(end);
        int x=end;
        while(x!=start)
        {
            x=p[x];
            path.push_back(x);
            x--;
        }
        reverse(path.begin(),path.end());
        for(i=0;i<path.size();i++){
                cout<<path[i]<<" ";
        }
     }
}