#include<stdio.h>long long dp[1<<19][19],ans;int n,m;int gr[19][19];int main(){    scanf("%d%d",&n,&m);    int bit,i,j;    for(i=0;i<m;i++){        int x,y;        scanf("%d%d",&x,&y);        x--,y--;        gr[x][y]=gr[y][x]=1;        if(x>y)dp[1<<y][x]=1;        else dp[1<<x][y]=1;    }    for(bit=1;bit<(1<<n);bit++){        int lastbit = 0;        while(!(1<<lastbit&bit))lastbit++;        for(i=lastbit+1;i<n;i++){            if(bit&1<<i)continue;            for(j=lastbit+1;j<n;j++){                if(gr[i][j])dp[bit|1<<i][j] += dp[bit][i];            }            if(gr[lastbit][i])ans += dp[bit][i];        }    }    printf("%lld",(ans-m)>>1);    return 0;}