#include<fstream.h>
#define max 100//001
struct graf
 {unsigned int nod;   
  graf *urm;   
 };   
graf *g[max];   
char viz[max];   
long cont;
void adauga(long x,long y)
{graf *p,*q;
p=new graf;
p->nod=y;
p->urm=g[x];
g[x]=p;
q=new graf;
q->nod=x;
q->urm=g[y];
g[y]=q;
}
void dfs(long x)
{graf *p=g[x];
viz[x]=1;
while(p) {if(!viz[p->nod]) dfs(p->nod);p=p->urm;}
}
int main()
{ifstream f("dfs.in");
ofstream g("dfs.out");
long n,m,i,x,y;
f>>n>>m;
for(i=1;i<=m;i++)
 {f>>x>>y;adauga(x,y);}
f.close();
for(i=1;i<=n;i++)
 if(!viz[i]){cont++;dfs(i);}
g<<cont<<'\n';
g.close();
return 0;
}