#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int n, m;
int in[300200], low[300200], cnt;
vector<int> v[300200];
stack<pair<int, int>> st;
vector<vector<pair<int, int>>> bcc;
set<int> ns;
int dfs(int u, int p){
in[u] = low[u] = ++cnt;
for(auto x : v[u]) if(x != p){
if(in[u] > in[x]) st.push({u, x});
if(in[x]) low[u] = min(low[u], in[x]);
else{
low[u] = min(low[u], dfs(x, u));
if(low[x] >= in[u]){
vector<pair<int, int>> b;
while(st.top() != make_pair(u, x)) b.push_back(st.top()), st.pop();
b.push_back(st.top()), st.pop();
if(b.size() > 1) bcc.push_back(b);
else ns.insert(b[0].first), ns.insert(b[0].second);
}
}
}
return low[u];
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m;
for(int i=1;i<=m;i++) {
int a, b; cin >> a >> b;
v[a].push_back(b), v[b].push_back(a);
}
dfs(1, 0);
ll ans = 0;
for(int i=1;i<=n;i++) if(m-(int)v[i].size() == n-2 && (bcc.empty() || !ns.count(i))) ans += i;
cout << ans;
}
