content: package v105;
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.ArrayList;
  import java.util.StringTokenizer;
  
  
  public class MorningWalk_UVa10596 {
  
  	static ArrayList<Integer>[] adjList;
  	
  	static boolean seen(int N)	//check if all edges can be visited 
  	{
  		for(int i = 0; i < N; ++i)
  			if(adjList[i].size() != 0)
  			{
  				dfs(i);
  				break;
  			}
  		for(int i = 0; i < N; ++i)
  			for(int j = 0; j < adjList[i].size(); ++j)
  				if(adjList[i].get(j) != null)
  					return false;
  		return true;
  	}
  	
  	static void dfs(int u)
  	{
  		for(int i = 0; i < adjList[u].size(); ++i)
  		{
  			Integer v = adjList[u].get(i);
  			if(v != null)
  			{
  				adjList[u].set(i, null);
  				dfs(v);
  			}
  		}
  	}
  	public static void main(String[] args) throws IOException {
  
  		Scanner sc = new Scanner(System.in);
  		PrintWriter out = new PrintWriter(System.out);
  		
  		while(sc.ready())
  		{
  			int N = sc.nextInt(), E = sc.nextInt();
  			boolean possible = E == 0 ? false : true;	//'single' walk
  			adjList = new ArrayList[N];
  			for(int i = 0; i < N; ++i)
  				adjList[i] = new ArrayList<Integer>();
  			while(E-->0)
  			{
  				int u = sc.nextInt(), v = sc.nextInt();
  				adjList[u].add(v);
  				adjList[v].add(u);
  			}
  			for(int i = 0; possible && i < N; ++i)
  				if((adjList[i].size() & 1) != 0)
  					possible = false;
  			out.println(possible&&seen(N)?"Possible":"Not Possible");
  		}
  		out.flush();
  	}
  	static class Scanner 
  	{
  		StringTokenizer st;
  		BufferedReader br;
  
  		public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}
  
  		public String next() throws IOException 
  		{
  			while (st == null || !st.hasMoreTokens()) 
  				st = new StringTokenizer(br.readLine());
  			return st.nextToken();
  		}
  
  		public boolean nextIsEmpty() throws IOException
  		{
  			String line = br.readLine();
  			if(line.isEmpty())
  				return true;
  			st = new StringTokenizer(line);
  			return false;
  		}
  
  		public int nextInt() throws IOException {return Integer.parseInt(next());}
  
  		public long nextLong() throws IOException {return Long.parseLong(next());}
  
  		public String nextLine() throws IOException {return br.readLine();}
  
  		public boolean ready() throws IOException {return br.ready(); }
  
  
  	}
  
  }
  