#include <iostream>
#include <fstream>
#include <list>

std::list<int> adj[100005];
int visited[100005];

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

// dfs algorithm
void dfs(int source) {
    visited[source] = 1;
    for (auto it = adj[source].begin();  it != adj[source].end(); it++) {
        if (!visited[*it]) {
            dfs(*it);
        }
    }
}


int main(void) {
    int n, m, nr_comp = 0;
    // read inputs
    fin >> n >> m;
    for (int i = 0; i < m; ++i) {
        int n1, n2;
        fin >> n1 >> n2;
        adj[n1].push_back(n2);
        adj[n2].push_back(n1);
    }

    for (int i = 1; i <= n; ++i) {
        if (visited[i] == 0) {
            nr_comp++;
            dfs(i);
        }
    }
    fout << nr_comp;
    fin.close();
    fout.close();
    return 0;
}