#include <iostream>
#include <fstream>
#include <vector>

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

void dfs(std::vector<std::vector<int>> const &adj, int node, std::vector<bool> &visited) {
    visited[node] = true;

    for(auto n : adj[node]) {
        if(!visited[n])
            dfs(adj, n, visited);
    }
}

int main() {
    int n, m;
    fin >> n >> m;
    std::vector<std::vector<int>> adj(n);
    while(m--) {
        int a, b;
        fin >> a >> b;
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    std::vector<bool> visited(n, false);
    int cnt{};
    for(int i = 0; i<n; i++) {
        if(!visited[i]) {
            cnt++;
            dfs(adj, i, visited);
        }
    }
    fout << cnt << '\n';
    return 0;
}