#include<fstream.h>
#include<conio.h>
#define NM 101

ifstream fin("dfs.in");
ofstream out("dfs.out");

struct nod{
int nr;
nod *next;
};

nod *l[NM],*urm[NM];
int n,m,viz[NM],cc;

void add(nod *&l,int x){
nod *nn=new(nod);
nn->nr=x;
nn->next=l;
l=nn;
}

void build(){
int i,x,y;
fin>>n>>m;
for(i=0;i<m;i++){
fin>>x>>y;
add(l[x],y);
add(l[y],x);}
}

void df(int x){
int y;
nod *nc=urm[x];
while(nc){
viz[x]=cc;
y=nc->nr;
nc=nc->next;
if(!viz[y])df(y);
urm[x]=nc;
}
}

void main(){
int i;
build();
for(i=1;i<=n;i++) urm[i]=l[i];
for(i=1;i<=n;i++) if(!viz[i]){cc++;df(i);}
out<<cc;
}