#include <bits/stdc++.h>

using namespace std;

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

vector<int> viz;
vector<vector<int> > v;
int n;

void dfs(int x, int nrv) {
    viz[x] = nrv;
    for(int i = 0; i < v[x].size(); i++) {
        if(!viz[v[x][i]])
            dfs(v[x][i], nrv);
    }
}

void read() {
    int a, b;
    int m;
    fin >> n >> m;
    v = vector<vector<int> >(n + 1);
    viz = vector<int>(n + 1, 0);
    for(int i = 1; i <= m; i++)
        fin >> a >> b, v[a].push_back(b), v[b].push_back(a);
}

void solve() {
    int nrv = 0; // la a cata comp conexa am ajuns
    for(int i = 1; i <= n; i++) {
        if(!viz[i])
            nrv++, dfs(i, nrv);
    }
    fout << nrv;
}

void fclose() {
    fin.close(), fout.close();
}

int main() {
    read();
    solve();
    fclose();
    return 0;
}