#include <bits/stdc++.h>
using namespace std;
ifstream in ("dfs.in");
ofstream out ("dfs.out");
bool viz[100001];
vector <int> v[100001];
void dfs (int nod)
{
    viz[nod] = 1;
    for (auto vecin:v[nod])
        if (!viz[vecin])
            dfs(vecin);
}
void solve ()
{
    int n, m;
    in >> n >> m;
    for (int i = 1;i<=m;++i)
    {
        int a, b;
        in >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int ans = 0;
    for (int i = 1;i<=n;++i)
        if (!viz[i])
        {
            dfs(i);
            ans++;
        }
    out << ans << '\n';
    return;
}
int main ()
{
    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}