#include<bits/stdc++.h>

using namespace std;

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

vector<vector<int>> adj(100005);
vector<int> vis(100005,0);

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

int main() {
    int n, m;
    fin >> n >> m;
    for (int i = 0 ; i < m ; i ++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

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