#include<iostream>
#include<cstdio>
#include<cstring>
#define maxn 100005
using namespace std;
int n,m;
int d[maxn];
int main()
{
	freopen("sent.in","r",stdin);
	freopen("sent.out","w",stdout);
	//freopen("in.txt","r",stdin);
    scanf("%d%d",&n,&m);
    int x,y;
    for(int i=1;i<=m;i++)
    {
    	scanf("%d%d",&x,&y);
    	d[x]++; d[y]++; 
    }
    int sum=0;
    for(int i=1;i<=n;i++) 
    if(d[i]&1) sum++; 
    if(!sum){ printf("0\n"); return 0;}
    sum=(sum-2)/2;
    printf("%d\n",sum);
    return 0;
}