#include <bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
#define all(a) a.begin(),a.end()
typedef long long ll;
typedef pair<ll,int> P;
typedef vector<ll> vi;
constexpr ll inf=1ll<<61;
constexpr ll mod=998244353;
typedef modint998244353 mi;

int main(){
    int n,m;cin>>n>>m;
    dsu d(n+n);
    rep(i,m){
        int a,b;cin>>a>>b;
        a--;b--;
        d.merge(a,b);
    }
    vector<vector<int>>G=d.groups();
    int ans=0;
    rep(i,n+n){
        ans+=G[i].size()%2;
    }
    cout<<ans/2<<endl;


}