#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> bool maximize(T &a, const T &b){ return (a < b ? a = b, 1 : 0); }
template<class T> bool minimize(T &a, const T &b){ return (a > b ? a = b, 1 : 0); }
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define all(x) x.begin(), x.end()
#define TASK "nonsense"
/// end of template ///
const int N = 1e5 + 10;
const int M = 2e5 + 10;
int n,m;
ii edge[M];
namespace sub1
{
bool check()
{
return (n<=1000 && m<=2000);
}
const int N = 1e3 + 10;
vector<int> adj[N];
bool vis[N];
int dep[N];
void dfs(int u)
{
vis[u]=1;
for(int v : adj[u]) if(!vis[v])
{
dep[v]=dep[u]+1;
dfs(v);
}
}
void solve()
{
int ans=0;
for(int tri=1;tri<=m;++tri)
{
for(int i=0;i<=n;++i) vector<int>().swap(adj[i]);
for(int i=1;i<=m;++i) if(i!=tri)
{
int u=edge[i].fi,v=edge[i].se;
adj[u].pb(v);
adj[v].pb(u);
}
adj[0].pb(edge[tri].fi);
adj[edge[tri].fi].pb(0);
adj[0].pb(edge[tri].se);
adj[edge[tri].se].pb(0);
memset(vis,0,sizeof(vis));
for(int i=0;i<=n;++i) if(!vis[i])
{
dep[i]=1;
dfs(i);
}
bool ok=1;
edge[0]={0,edge[tri].fi};
edge[m+1]={0,edge[tri].se};
for(int i=0;i<=m+1;++i) if(i!=tri)
{
int du=dep[edge[i].fi];
int dv=dep[edge[i].se];
ok&=((du&1)!=(dv&1));
}
ans+=ok;
}
cout<<ans;
}
}
namespace subfull
{
vector<ii> adj[N];
int dep[N],parId[N],sum[N][2],num[2],pass[M][2];
void dfs(int u)
{
for(ii p : adj[u]) if(dep[p.fi]==-1)
{
// cout<<u<<' '<<p.fi<<'\n';
dep[p.fi]=dep[u]+1;
parId[p.fi]=p.se;
dfs(p.fi);
}
}
void work(int u)
{
for(ii p : adj[u]) if(parId[p.fi]==p.se)
{
work(p.fi);
for(int j=0;j<2;++j) sum[u][j]+=sum[p.fi][j];
}
if(parId[u]!=-1)
{
pass[parId[u]][0]=sum[u][0];
pass[parId[u]][1]=sum[u][1];
}
}
void solve()
{
for(int i=1;i<=m;++i)
{
adj[edge[i].fi].pb({edge[i].se,i});
adj[edge[i].se].pb({edge[i].fi,i});
}
memset(dep,-1,sizeof(dep));
memset(parId,-1,sizeof(parId));
for(int i=1;i<=n;++i) if(dep[i]==-1)
{
dep[i]=1;
dfs(i);
}
for(int i=1;i<=m;++i)
{
int u=edge[i].fi,v=edge[i].se;
if(dep[u]>dep[v]) swap(u,v);
if(parId[v]!=i)
{
bool con=((dep[u]&1)!=(dep[v]&1));
++sum[v][con];
--sum[u][con];
++num[con];
++pass[i][con];
}
}
for(int i=1;i<=n;++i) if(dep[i]==1) work(i);
int ans=0;
for(int i=1;i<=m;++i) if((pass[i][0]==num[0]) && pass[i][1]==0) ++ans;
cout<<ans;
}
}
void solve()
{
cin>>n>>m;
for(int i=1;i<=m;++i) cin>>edge[i].fi>>edge[i].se;
// if(sub1::check()) return void(sub1::solve());
return void(subfull::solve());
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen(TASK".inp","r",stdin);
// freopen(TASK".out","w",stdout);
int testcase=1;
// cin>>testcase;
while (testcase--)
solve();
return 0;
}
