#include <bits/stdc++.h>
using namespace std;

static constexpr int NMAX = (int)1e5 + 5; // 10^5 + 5 = 100.005
int n, m;
vector<int> adj[NMAX];
vector<int> viz;

void DFS(int node) {
    viz[node] = 1;

    for (int i = 0; i < adj[node].size(); i++) {
        int neigh = adj[node][i];
        if (viz[neigh] == 0) {
            DFS(neigh);
        }
    }
}

int get_result() {
    int nr = 0;
    viz.resize(n + 1, 0);

    for (int i = 1; i <= n; i++) {
        if (viz[i] == 0) {
            nr++;
            DFS(i);
        }
    }
    return nr;
}


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

    fin >> n >> m;
    for (int i = 1, x, y; i <= m; i++) {
        fin >> x >> y; // muchie (x, y)
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    fout << get_result();

    fin.close();
    fout.close();

    return 0;
}