#include <bits/stdc++.h>

using namespace std;


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

int n, m;
vector<vector<int>> adj;
vector<int> viz;


void DFS(int nod) {
    viz[nod] = 1;
    for (int i : adj[nod])
        if (!viz[i])
            DFS(i);
}

int main()
{
    fin >> n >> m;
    adj.resize(n + 5);
    viz.resize(n + 5);
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int cnt_comp=0;
    for (int i = 1; i <= n; i++)
        if (!viz[i]) {     /// echiv. viz[i] == 0
            cnt_comp++;
            DFS(i);
        }
    fout << cnt_comp << "\n";
    return 0;
}