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

int n,m;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector<vector<int>>adj;
vector<int>viz;

void DFS(int nod) {
    viz[nod]=1;
    for (int i:adj[nod])
        if (viz[i]==0)
            DFS(i);
}

int main() {
    int cnt=0;
    f >> n >> m;
    adj.resize(n+5);
    viz.resize(n+5);
    for (int i=1;i<=m;i++) {
        int x,y;
        f>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    for (int i=1;i<=n;i++)
        if (viz[i]==0) {
            DFS(i);
            cnt++;
        }

    g<<cnt;

    return 0;
}