source_code: import java.io.PrintWriter;
  import java.util.Scanner;
  
  public class D {
  
      public void run(Scanner in, PrintWriter out) {
          int n = in.nextInt();
          int[][] graph = new int[n][n];
          int m = in.nextInt();
          for (int i = 0; i < m; i++) {
              int x = in.nextInt() - 1;
              int y = in.nextInt() - 1;
              graph[x][y] = 1;
              graph[y][x] = 1;
          }
          long[][] dyn = new long[1 << n][n];
          for (int i = 0; i < n; i++) {
              dyn[1 << i][i] = 1;
          }
          long answer = 0;
          for (int mask = 1; mask < 1 << n; mask++) {
              int start = Integer.numberOfTrailingZeros(mask);
              for (int i = 0; i < n; i++) {
                  if ((mask & (1 << i)) == 0) continue;
                  for (int j = start + 1; j < n; j++) {
                      if (graph[i][j] > 0 && (mask & (1 << j)) == 0) {
                          dyn[mask + (1 << j)][j] += dyn[mask][i];
                      }
                  }
                  if (graph[i][start] > 0) {
                      answer += dyn[mask][i];
                  }
              }
          }
          out.println((answer - m)/ 2);
      }
  
      public static void main(String[] args) {
          try (Scanner in = new Scanner(System.in);
               PrintWriter out = new PrintWriter(System.out)
          ) {
              new D().run(in, out);
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  }
  