#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int vizit[100010],n,m,dim[100010],conex;
vector <int> a[100010];

void dfs(int nod)
{
    int i;
    for (i=0;i<dim[nod];i++)
    {
        if (vizit[a[nod][i]]==0) {
            vizit[a[nod][i]]=1;
            dfs ( a[nod][i]);
        }
    }
}


int main()
{
    int i,j;
    int x,y;
    f>>n>>m;
 for (i=1;i<=m;i++)
 {
    f>>x>>y;
    a[x].push_back(y);
    a[y].push_back(x);
 }
 for (i=1;i<=n;i++)
 {
     dim[i]=a[i].size();
 }

    for (i=1;i<=n;i++)
    {
        if (vizit[i]==0)
        {
            conex++;
            dfs(i);
        }
    }
g<<conex;

    return 0;
}