#include<iostream>

#include<cstring>

#include<cstdio>

using namespace std;

const int maxn = *;

int du[maxn],num[maxn],fa[maxn];

int MAX(int x,int y)

{

    return x>y?x:y;

}

int f(int x)

{

    if(fa[x]==) return x;

    else return fa[x]=f(fa[x]);

}

void Init()

{

    memset(du,,sizeof(du));

    memset(num,,sizeof(num));

    memset(fa,,sizeof(fa));

}

int main(void)

{

    int n,m,t1,t2,i,j,x,y;

    while(~scanf("%d%d",&n,&m)){

        Init();

        for(i=;i<=m;i++){

            scanf("%d%d",&x,&y);

            du[x]++;du[y]++;

            t1=f(x);t2=f(y);

            if(t1!=t2) fa[t2]=t1;

        }

        for(i=;i<=n;i++)

        if(du[i]%) num[f(i)]++;

        int cnt=;

        for(i=;i<=n;i++)

        if(fa[i]==&&du[i]) cnt+=MAX(,num[i]/);

        printf("%d\n",cnt);

    }

    return ;

}