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

using namespace std;

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

const int NMAX = 1e5 + 5;
vector<int> g[NMAX];
int n, m, res;
bool vis[NMAX];

void dfs(int nod) {
    vis[nod] = true;
    for (auto nxt : g[nod]) {
        if (!vis[nxt]) {
            vis[nxt] = true;
            dfs(nxt);
        }
    }
}

int main() {

    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }

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

    fout << res;

    return 0;
}