#include <bits/stdc++.h>
using namespace std;

int noduri, muchii, ans, fr[100010];
vector<int> vecini[100010];

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

void DFS(int x) {
    if (fr[x] == 0) {
        fr[x] = 1;
        for (int j = 0; j < vecini[x].size(); ++j) {
            DFS(vecini[x][j]);
        }
    }
}

int main() {
    fin.tie(0);
    ios::sync_with_stdio(0);
    fin >> noduri >> muchii;
    for (int i = 1; i <= muchii; ++i) {
        int x, y;
        fin >> x >> y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
    for (int i = 1; i <= noduri; ++i) {
        if (fr[i] == 0) {
            DFS(i);
            ++ans;
        }
    }
    fout << ans;
    return 0;
}