#include <iostream>
#include <fstream>
#include <vector>
using namespace std;


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

int n, m, conex;
vector <vector<int>> v;
vector <bool> visited;

void read() {
    fin >> n >> m;
    v = vector<vector<int>>(n + 1);
    visited = vector <bool> (n + 1);
    for(int i = 1; i <= m; ++i) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int node) {
    visited[node] = true;
    for(const auto& neighbour : v[node]) {
        if(!visited[neighbour])
            dfs(neighbour);
    }
}

int main() {
    read();
    for(int i = 1; i <= n; i ++) {
        if (!visited[i]) {
            dfs(i);
            conex++;
        }
    }
    fout << conex;
}