#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n, m, x, y, vis[100005], ans = 0;
vector <int> v[100005];

void dfs (int k) {
    vis[k] = 1;
    for (auto x: v[k])
        if (!vis[x])
            dfs (x);
}

int main()
{
    f >> n >> m;
    for (int i=1; i<=m; ++i)
    {
        f >> x >> y;
        v[x].push_back (y);
        v[y].push_back (x);
    }
    for (int i=1; i<=n; ++i)
        if (!vis[i]) {
            ++ans;
            dfs (i);
        }
    g << ans;
    return 0;
}