100 10
87 73
15 71
14 33
1 4
20 80
65 67
36 36
25 4
22 21
7 97
 4 2
3 3
3 4
 5 4
3 3
4 4
5 5
1 2
 4 4
1 2
2 3
3 1
4 4
 4 3
1 1
2 3
3 4
 1000000 1
255765 255765
 4 3
1 2
2 3
4 4
 4 2
1 1
1 2
 3 3
1 1
2 2
3 3
 5 4
1 1
2 3
2 4
2 5
 4 5
1 4
3 4
1 2
2 3
2 4
 4 4
2 3
2 4
3 4
4 4
 10 9
8 10
3 10
2 8
9 3
4 8
1 10
7 9
5 4
7 3
 10 10
1 2
2 3
3 4
4 5
5 1
6 6
7 7
8 8
9 9
10 10
 5 5
1 4
3 4
1 2
2 3
2 4
 3 3
1 2
2 2
3 3
 5 3
1 1
2 2
3 3
 6 12
1 2
1 3
2 3
1 1
2 2
3 3
4 5
5 6
4 6
4 4
5 5
6 6
 4 4
1 2
2 3
1 3
4 4
 5 4
1 2
3 3
4 4
5 5
 7 13
6 7
2 7
3 7
4 3
5 2
1 4
7 7
3 1
5 5
3 3
1 5
2 6
6 6
 2 2
1 1
2 2
 5 5
1 1
2 2
3 3
4 4
5 5
 1 1
1 1
 7 3
1 1
3 3
6 6
 3 3
1 1
2 3
3 3

0 1 0 0 0 0 0 1 0 0 8 6 12 0 8 0 0 0 0 0 57 0 0 0 0 0
import java.io.*;
import java.util.*;

public class Problem implements Runnable {
    int n,k=0, m;
    ArrayList<Integer>[] g;
    boolean[] vis;
    private void solve() throws IOException {
        n=readInt(); m=readInt();
        g=new ArrayList[n];
        for (int i=0;i<n;i++)
            g[i]=new ArrayList<>();
        for (int i=0;i<m;i++){
            int u=readInt()-1,v=readInt()-1;
            if (u!=v) {
                g[u].add(v);
                g[v].add(u);
            }
        }
        vis=new boolean[n];
        vis[0]=true;
        dfs(0);
        boolean s=true;
        for (int i=0;i<n;i++)
            if (!vis[i]) s=false;
        if (!s) out.print(0);
        else out.print(fact(k)/2/fact(k-2));
    }
    long fact(long n){
        long ans=1;
        for (long i=2;i<=n;i++)
            ans*=i;
        return ans;
    }
    void dfs(int v){
        if (g[v].size()<2) k++;
        for (int to:g[v])
            if (!vis[to]){
            vis[to]=true;
            dfs(to);
            }
    }
    public static void main(String[] args) throws IOException {
        new Problem().run();
    }

    private void init() throws FileNotFoundException {
        Locale.setDefault(Locale.US);
        String fileName = "";
        if (fileName.isEmpty()) {
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        } else {
            in = new BufferedReader(new FileReader(fileName + ".in"));
            out = new PrintWriter(fileName + ".out");
        }
    }

    public void run() {
        try {
            init();
            solve();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(-1);
        }
    }

    private static BufferedReader in;
    private static StringTokenizer tok;
    private static PrintWriter out;

    private static String readToken() throws IOException {
        while (tok == null || !tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }

    private static int readInt() throws IOException {
        return Integer.parseInt(readToken());
    }

    private static double readDouble() throws IOException {
        return Double.parseDouble(readToken());
    }

    private static long readLong() throws IOException {
        return Long.parseLong(readToken());
    }
}