#include <cstdio>
#include <vector>
using namespace std;
vector <vector <int> > muchii;
vector <bool> viz;
int n,m;
void citire_graf()
{
    int i,a,b;
    scanf("%d%d",&n,&m);
    muchii.resize(n);
    viz.resize(n);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        a--;
        b--;
        muchii[a].push_back(b);
        muchii[b].push_back(a);
    }
}
void parcurg_dfs(int nod)
{
    int i,next;
    viz[nod]=1;
    for(i=0;i<muchii[nod].size();i++)
    {
        next=muchii[nod][i];
        if(!viz[next])
            parcurg_dfs(next);
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int comp_conexe=0,i;
    citire_graf();
    for(i=0;i<muchii.size();i++)
    {
        if(!viz[i])
        {
            comp_conexe++;
            parcurg_dfs(i);
        }
    }
    printf("%d",comp_conexe);
    return 0;
}