#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int number=0;
int numberOf(vector<vector<int>> mygraph,int current,int n, vector<bool> visited)
{

    vector<int> :: iterator itr;
    visited[current]=true;
    int count =1;
    for(itr=mygraph[current].begin();itr!=mygraph[current].end();itr++)
    {
        if(!visited[*itr])
        {
        count += numberOf(mygraph,*itr,n,visited);
        }
    }
    if(count%2==0)
    {
        number++;
    }
    return count;
}
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    int n;
    int m;
    cin>>n>>m;
    vector<vector<int>> mygraph(n);
     vector<bool> visited(n,false);
    for(int i=0;i<m;i++)
    {
        int from;
        int to;
        cin>>from>>to;
        mygraph[from-1].push_back(to-1);
        mygraph[to-1].push_back(from-1);

    }
    numberOf(mygraph,0,n,visited);
    cout<<number-1;
    return 0;
}