#include <fstream>
using namespace std;
#define max 100002
ifstream f("dfs.in");
ofstream g("dfs.out");

struct nod{int info; 
           nod *urm;};
char v[max];
int n,comp_con,m,i;
nod *l[max];

void adaugare(nod *&p, int x)
{nod *c;
c=new nod;
c->info=x;
c->urm=0;
if (p!=0) 
p=c;
else
{c->urm=p;
p=c;
}
}

void df(int i)
{nod *c;
v[i]=1;
c=l[i];
while (c)
{if(v[c->info]!=0)
df(c->info);
c=c->urm;
}
}

int main()
{int x,y;
f>>n>>m;
for(i=1;i<=m;i++)
{f>>x>>y;
adaugare(l[x],y);
adaugare(l[y],x);
}
for(i=1;i<=n;i++)
if(v[i]==0) 
{comp_con++;
 df(i);}
g<<comp_con;
f.close();
g.close();
return 0;

}