#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);

}