#include <bits/stdc++.h>

using namespace std;

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

int n, m, s, a, b;
vector< vector<int> > lv;
vector<bool> visited;

void dfs(int x)
{
    if (visited[x])
        return;

    visited[x] = true;

    for (auto nx : lv[x])
        dfs(nx);
}

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

    lv.resize(n + 1);
    visited.resize(n + 1, 0);

    while (m--)
        f >> a >> b,
        lv[a].push_back(b),
        lv[b].push_back(a);

    int cnt = 0;
    for (int i = 1; i <= n; ++i)
        if (!visited[i])
            dfs(i),
            ++cnt;

    g << cnt;

    return 0;
}