source_code: 
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.StreamTokenizer;
  
  public class ASimpleTask {
  
  	static StreamTokenizer st;
  
  	static int nextInt() {
  		try {
  			st.nextToken();
  		} catch (IOException e) {
  			// TODO Auto-generated catch block
  			e.printStackTrace();
  		}
  		return (int) st.nval;
  	}
  
  	static int[][] edges;
  	static long[][] dp;
  
  	public static void main(String[] args) {
  		st = new StreamTokenizer(new BufferedReader(new InputStreamReader(
  				System.in)));
  
  		int n = nextInt();
  		int m = nextInt();
  
  		edges = new int[n][n];
  
  		for (int i = 0; i < m; i++) {
  			int from = nextInt() - 1;
  			int to = nextInt() - 1;
  			edges[from][to] = edges[to][from] = 1;
  		}
  
  		dp = new long[(1 << n) + 1][n + 1];
  
  		for (int mask = 1; mask < (1 << n); mask++) {
  			for (int i = 0; i < n; i++) {
  				if (Integer.bitCount(mask) == 1 && (mask & (1 << i)) != 0) {
  					dp[mask][i] = 1;
  					continue;
  				}
  
  				if (Integer.bitCount(mask) > 1 && (mask & (1 << i)) != 0
  						&& first(mask, n) != i) {
  					for (int j = 0; j < n; j++) {
  						if (edges[i][j] == 1) {
  							dp[mask][i] += dp[mask ^ (1 << i)][j];
  						}
  					}
  				}
  			}
  		}
  
  		long count = 0;
  		for (int mask = 1; mask < (1 << n); mask++) {
  			for (int i = 0; i < n; i++) {
  				if (Integer.bitCount(mask) >= 3
  						&& edges[i][first(mask, n)] != 0)
  					count += dp[mask][i];
  			}
  		}
  
  		System.out.println(count / 2);
  
  	}
  
  	static int first(int mask, int n) {
  		for (int i = 0; i < n; i++) {
  			if ((mask & (1 << i)) != 0)
  				return i;
  		}
  		return -1;
  	}
  
  }
  