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

vector<int> vis;
vector<vector<int>> L;

void DFS(int nod){
    vis[nod] = 1;
    for(int x : L[nod]){
        if(vis[x] == 0)
            DFS(x);
    }
}

int main() {
    int n, m;
    
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f >> n >> m;
    
    L.resize(n);
    vis.resize(n);

    for(int i = 0; i < m; i++){
        int x,y;
        f >> x >> y;
        L[x-1].push_back(y-1);
        L[y-1].push_back(x-1);
    }

    int nr = 0;
    for(int i = 0; i < n; i++){
        if(vis[i]==0){
            nr++;
            DFS(i);
        }
    }
    g << nr;
    f.close();
    g.close();
    return 0;
}