#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e5+5;
vector<int> e[N];
bool vis[N];
int fe[N],sum[N];
int ans;
int df(int u){
    vis[u]=1;
    int res=1;
    for(auto v:e[u]){
        if(vis[v]) continue;
        res+=df(v);
    }
    return res;
}
int dfs(int u){
    vis[u]=1;
    int res=1;
    for(auto v:e[u]){
        if(vis[v]) continue;
        res+=dfs(v);
    }
    vis[u]=0;
    return res;
}
void dfs1(int u,int s){
    vis[u]=1;
    int sg=s;
    for(auto v:e[u]){
        sg^=dfs(v)%2==0?2:1;
    }
    if(sg==0){
        ans++;
    }
    vis[u]=0;
}
bool vvis[N];
void ddfs(int u,int s){
    vvis[u]=1;
    dfs1(u,s);
    for(auto v:e[u]){
        if(vvis[v]) continue;
        ddfs(v,s);
    }
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int n,m;cin>>n>>m;
    for(int i=1;i<=m;i++){
        int u,v;cin>>u>>v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    int cnt=0;
    for(int i=1;i<=n;i++){
        if(vis[i]) continue;
        fe[++cnt]=i;
        sum[cnt]=df(i);
        //cout<<"sum["<<cnt<<"]="<<sum[cnt]<<endl;
    }
    int sg=0;
    for(int i=1;i<=cnt;i++){
        sg^=(sum[i]%2==0?2:1);
    }
    for(int i=1;i<=n;i++)vis[i]=0;
    for(int i=1;i<=cnt;i++){
        int s=sg^(sum[i]%2==0?2:1);
        int _in=fe[i];
        //cout<<"_in="<<_in<<endl;
        ddfs(_in,s);
        if(sum[i]%2==1&&s^3==0)ans+=sum[i]-1;
        else if(sum[i]%2==0&&s==0)ans+=sum[i]-1;
    }
    cout<<ans<<endl;
    return 0;
}