#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5;
vector<int>g[NMAX + 5];
bitset<NMAX + 5>vis;

void dfs (int u)
{
    vis[u] = true;
    for (const auto &v : g[u])
    {
        if (!vis[v])
            dfs(v);
    }
}

int main()
{
    int n, m;
    in >> n >> m;

    while (m--)
    {
        int u, v;
        in >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    int ans = 0;
    for (int i=1; i<=n; i++)
    {
        if (!vis[i])
            ans++, dfs(i);
    }

    out << ans;

    return 0;
}