#include <fstream>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

int n, viz[100001];

struct nod
{
    int val;
    nod*urm;
}*L[100001];

void addnod(int x, int y)
{
    nod *p=new nod;
    p->val=y;
    p->urm=L[x];
    L[x]=p;
}

void dfs(int i)
{
    viz[i]=1;
    for(nod *p=L[i]; p; p=p->urm)
        if(viz[p->val]==0)
            dfs(p->val);
}

int main()
{
    int x, y, m;
    f>>n>>m;
    while(m--)
    {
        f>>x>>y;
        addnod(x,y);
        addnod(y,x);
    }
    int nrCC=0;
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            dfs(i);
            nrCC++;
        }
    g<<nrCC;
    return 0;
}