import java.util.Arrays; import java.util.HashMap; import java.util.Map; public class Main { private static int mod = 998244353; private static long inv2 = invl(2, mod); private static int[][] fif; private static long[] p2; private static int[] from; private static int[] to; private static int n; private static int m; private static int k; private static void solve() { n = ni(); m = ni(); from = new int[m]; to = new int[m]; for (int i = 0; i < m; i++) { from[i] = ni() - 1; to[i] = ni() - 1; } fif = enumFIF(n * 2, mod); p2 = new long[n + 1]; p2[0] = 1; for (int i = 1; i <= n; i++) { p2[i] = p2[i - 1] * 2 % mod; } k = m * 2; int[][][][] cnt = new int[k + 1][m + 1][2][2]; for (int i = 0; i < 1 << m; i++) { int[] v = f(i); cnt[v[0]][v[1]][v[2]][v[3]]++; } long ret = 0; for (int i = 0; i <= k; i++) { for (int j = 0; j <= m; j++) { for (int s = 0; s < 2; s++) { for (int t = 0; t < 2; t++) { if (cnt[i][j][s][t] == 0) continue; long now = g(i, j, t == 1) * cnt[i][j][s][t] % mod; long x = s == 0 ? 1 : -1; ret += mod + x * now; ret %= mod; } } } } System.out.println(ret); } private static long g(int v, int u, boolean loop) { if (loop) { return 1; } long ret = 0; int nlast = n - v; for (int i = Math.max(0, 3 - v); i <= nlast; i++) { long now = CX(nlast, i, mod, fif); now = now * p2[u] % mod; now = now * fif[0][i + u - 1] % mod; now = now * inv2 % mod; ret += now; ret %= mod; } return ret; } private static int[] f(int s) { Map map = new HashMap<>(); int cnt = 0; int[] deg = new int[k]; DisjointSet uf = new DisjointSet(k); boolean loop = false; for (int i = 0; i < m; i++) { if ((s >> i & 1) == 1) { int a = from[i]; int b = to[i]; if (!map.containsKey(a)) { map.put(a, cnt++); } if (!map.containsKey(b)) { map.put(b, cnt++); } a = map.get(a); b = map.get(b); if (deg[a] == 2 || deg[b] == 2 || loop && uf.equiv(a, b)) { return null; } if (!loop && uf.equiv(a, b)) { loop = true; } deg[a]++; deg[b]++; uf.union(a, b); } } int v = 0; for (int i = 0; i < cnt; i++) { if (uf.upper[i] < 0) { v++; } } return new int[] { cnt, v, Integer.bitCount(s) % 2, loop ? 1 : 0 }; } private static long invl(long a, long mod) { long b = mod; long p = 1, q = 0; while (b > 0) { long c = a / b; long d; d = a; a = b; b = d % b; d = p; p = q; q = d - c * q; } return p < 0 ? p + mod : p; } public static class DisjointSet { public int[] upper; // minus:num_element(root) plus:root(normal) // public int[] w; public DisjointSet(int n) { upper = new int[n]; Arrays.fill(upper, -1); } public DisjointSet(DisjointSet ds) { this.upper = Arrays.copyOf(ds.upper, ds.upper.length); } public int root(int x) { return upper[x] < 0 ? x : (upper[x] = root(upper[x])); } public boolean equiv(int x, int y) { return root(x) == root(y); } public boolean union(int x, int y) { x = root(x); y = root(y); if (x != y) { if (upper[y] < upper[x]) { int d = x; x = y; y = d; } upper[x] += upper[y]; upper[y] = x; } return x == y; } } public static long CX(long n, long r, int p, int[][] fif) { if (n < 0 || r < 0 || r > n) return 0; int np = (int) (n % p), rp = (int) (r % p); if (np < rp) return 0; if (n == 0 && r == 0) return 1; int nrp = np - rp; if (nrp < 0) nrp += p; return (long) fif[0][np] * fif[1][rp] % p * fif[1][nrp] % p * CX(n / p, r / p, p, fif) % p; } public static int[][] enumFIF(int n, int mod) { int[] f = new int[n + 1]; int[] invf = new int[n + 1]; f[0] = 1; for (int i = 1; i <= n; i++) { f[i] = (int) ((long) f[i - 1] * i % mod); } long a = f[n]; long b = mod; long p = 1, q = 0; while (b > 0) { long c = a / b; long d; d = a; a = b; b = d % b; d = p; p = q; q = d - c * q; } invf[n] = (int) (p < 0 ? p + mod : p); for (int i = n - 1; i >= 0; i--) { invf[i] = (int) ((long) invf[i + 1] * (i + 1) % mod); } return new int[][] { f, invf }; } public static void main(String[] args) { new Thread(null, new Runnable() { @Override public void run() { long start = System.currentTimeMillis(); String debug = args.length > 0 ? args[0] : null; if (debug != null) { try { is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug)); } catch (Exception e) { throw new RuntimeException(e); } } reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768); solve(); out.flush(); tr((System.currentTimeMillis() - start) + "ms"); } }, "", 64000000).start(); } private static java.io.InputStream is = System.in; private static java.io.PrintWriter out = new java.io.PrintWriter(System.out); private static java.util.StringTokenizer tokenizer = null; private static java.io.BufferedReader reader; public static String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new java.util.StringTokenizer(reader.readLine()); } catch (Exception e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } private static double nd() { return Double.parseDouble(next()); } private static long nl() { return Long.parseLong(next()); } private static int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = ni(); return a; } private static char[] ns() { return next().toCharArray(); } private static long[] nal(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nl(); return a; } private static int[][] ntable(int n, int m) { int[][] table = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[i][j] = ni(); } } return table; } private static int[][] nlist(int n, int m) { int[][] table = new int[m][n]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[j][i] = ni(); } } return table; } private static int ni() { return Integer.parseInt(next()); } private static void tr(Object... o) { if (is != System.in) System.out.println(java.util.Arrays.deepToString(o)); } }