#include <vector>
#include <fstream>

using namespace std;

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

void fill_visited_from(int node, const vector<vector<int>>& graph, vector<bool>& visited) {
    visited[node] = true;
    for (int neighbor : graph[node]) {
        if (!visited[neighbor]) {
            fill_visited_from(neighbor, graph, visited);
        }
    }
}

int main() {
    int n, m, conex_count = 0;
    fin >> n >> m;

    vector<vector<int>> graph(n + 1);
    for (int i = 0; i < m; ++i) {
        int u, v;
        fin >> u >> v;
        graph[u].push_back(v);
        graph[v].push_back(u); 
    }

    vector<bool> visited(n + 1, false);

    for (int i = 1; i <= n; ++i) {
        if (!visited[i]) {
            conex_count++;
            fill_visited_from(i, graph, visited);
        }
    }
    fout << conex_count << endl;

    return 0;
}