#include <cstdio>
	
 
	
int i,n,m,v[100001],x,y,aux,nr=0;
	
FILE*f=freopen("dfs.in","r",stdin);
	
FILE*g=freopen("dfs.out","w",stdout);
	
 
	
int main()
	
{
	
    scanf("%d %d", &n, &m);
	
 
	
    for(i=1; i<=n; i++)   v[i]=i;
	
    for(i=1;i<=m;i++)
	
    {scanf("%d %d", &x, &y);
	
     while(x!=v[x]) aux=v[v[x]],v[x]=aux,x=aux;
	
     while(y!=v[y]) aux=v[v[y]],v[y]=aux,y=aux;
	
     if(x!=y){
	
            nr++; v[x]=y;
	
        }
	
    }
	
    printf("%d\n" ,n-nr);
	
}