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

using namespace std;

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

const int NMAX = 100'001;

int n, m, vis[NMAX], cnt;
vector < int > G[NMAX];

void dfs(int node) {
    vis[node] =  cnt;

    for(int neighbour : G[node])
        if(!vis[neighbour])
            dfs(neighbour);
}

int main() {

    f >> n >> m;

    while(m--) {
        int x, y;
        f >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    g << cnt << '\n';

    return 0;
}