#include <iostream>
#include <fstream>

using namespace std;

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

struct nod
{
    int info;
    nod *urm;
}*prim[100005];

int n,m,viz[100005];

void adin(nod *&prim,int x)
{
    nod *nou=new nod;
    nou->info=x;
    nou->urm=prim;
    prim=nou;
}

void citire()
{
    int x,y,i;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        adin(prim[x],y);
        adin(prim[y],x);
    }
}

void DFS(int x)
{
    viz[x]=1;
    for(nod *q=prim[x];q;q=q->urm)
        if(viz[q->info]==0) DFS(q->info);
}

int main()
{
    int nrc=0;
    citire();
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
    {
        nrc++;
        DFS(i);
    }
    fout<<nrc;
    return 0;
}