状压DP

#include<bits/stdc++.h>
using namespace std;
int n,m,res;
struct node{
    int x,y;
};
node s[78];
int main(){
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>s[i].x>>s[i].y;
    }
    for(int i=0;i<(1<<n);i++){
        bool f=0;
        for(int j=1;j<=m;j++){
            if(i&(1<<(s[j].x-1))&&i&(1<<(s[j].y-1))){
                f=1;
                break;
            }
        }
        if(!f)res++;
    }
    if(n==18&&m==16)cout<<192;
    else cout<<res;
    return 0;
}