#include <bits/stdc++.h>
using namespace std;

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

const int nmax = 1e5 + 3;

int viz[nmax], n, m, a, b, sol;

vector <int> v[nmax];

void dfs(int nod)
{
    viz[nod] = 1;
    for (int i = 0; i < v[nod].size(); ++i)
    {
        int urm = v[nod][i];

        if (viz[urm])
            continue;
        dfs(urm);
    }
}

int main()
{
    f >> n >> m;

    while (m--)
    {
        f >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    for (int i = 1; i <= n; ++i)
    {
        if (viz[i])
            continue;

        ++sol;
        dfs(i);
    }

    g << sol;

    return 0;
}