#include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define mt make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)< pii; typedef vector vi; typedef vector vll; int vis[55], e[55][55], adj[55][55]; vi G[55]; set ps; vi path; void dfs(int u, int d, int s) { path.push_back(u); vis[u] = 1; each(v, G[u]) { if(vis[v] == 1 && d == 3 && v == s) { auto p = path; // rep(i, 4)cout << p[i] << ' '; // cout << endl; bool ok = true; rep(i, 4) { e[p[i]][p[(i + 1) % 4]] = 1; e[p[(i + 1) % 4]][p[i]] = 1; } // e以外に関係があっては駄目 rep(i, 4)rep(j, 4) { if(e[p[i]][p[j]] != adj[p[i]][p[j]]) { ok = false; break; } } rep(i, 4) { e[p[i]][p[(i + 1) % 4]] = 0; e[p[(i + 1) % 4]][p[i]] = 0; } if(ok) { sort(all(p)); ps.insert(p); } } if(!vis[v] && d < 3) { dfs(v, d + 1, s); } } vis[u] = 2; path.pop_back(); } int main(){ ios::sync_with_stdio(false); cin.tie(0); int N, M; cin >> N >> M; rep(i, M) { int a, b; cin >> a >> b; G[a].push_back(b); G[b].push_back(a); adj[a][b] = adj[b][a] = 1; } rep(i, N) { MEM(vis, 0); dfs(i, 0, i); } /* each(p, ps) { rep(i, 4)cout << p[i] << ' '; cout << endl; }*/ cout << sz(ps) << endl; }