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

using namespace std;

vector<set<int>> g(100000);
vector<int> visited(100000);
int components;


void dfs(int node) {
    visited[node] = 1;

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


int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n, m;
    
    in >> n >> m;

    int a, b;
    for (int i = 1; i <= m; ++i) {
        in >> a >> b;
        g[a].insert(b);
        g[b].insert(a);
    }


    for (int i = 1; i <= n; ++i) {
        if (!visited[i]) {
            components++;
            dfs(i);
        }
    }

    out << components;
}