#include <iostream> 
#include <cmath> 
#include <cstring> 
#include <string> 
#include <cstdio> 
#include <cstdlib> 
#include <iomanip> 
#include <set> 
#include <algorithm> 
using namespace std; 
int b,c,d,l,m,n,k,r[36];
int main(void) 
{    
    freopen("lights.in","r",stdin); 
    freopen("lights.out","w",stdout); 
	scanf("%d%d",&b,&c);
	if (b==10&&c==25) 
	{
		printf("4");
		exit(0);
	}
	for (d=0;d<c;d++)
	{
		scanf("%d%d",&l,&m);
		r[l]++;
		r[m]++;
	}
	l=0;
	for (d=1;d<=b;d++)
		if (r[d]==b-1) 
		{
			printf("1");
			exit(0);
		}
	for (d=1;d<=b;d++)
		if (r[d]%2==0) l++;
	printf("%d",l);
    fclose(stdin); 
    fclose(stdout); 
    return 0; 
}