#include <bits/stdc++.h>

using namespace std;

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




int n, m, cnt, viz[100005];


vector<vector<int>> adj;
vector<int> sources;
vector<pair<int, int>> dist;


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

int main() {
    fin >> n >> m;
    adj.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);
    }
    for (int i = 1; i <= n ; i++)
        if(!viz[i]) {
            cnt++;
            DFS(i);
        }
    fout << cnt << "\n";
    return 0;
}