#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

vector <vector <int> > a(100002);
vector <bool> viz(100002, false);
int n, m, nrcomp;
void read()
{
    ifstream f("dfs.in");
    f >> n >> m;
    for(int i=0, x, y; i<m; ++i)
    {
        f >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    f.close();
}

void DFS(int x)
{
    viz[x]=true;
    for(int i=0; i<a[x].size(); ++i)
    {
        if(!viz[a[x][i]])
            DFS(a[x][i]);
    }
}

void solve()
{
    for(int i=1; i<=n; ++i)
    {
        if(!viz[i])
        {
            ++nrcomp;
            DFS(i);
        }
    }
    ofstream g("dfs.out");
    g << nrcomp << '\n';
}

int main()
{
    read();
    solve();
    return 0;
}