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

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

const int nmax = 1e5+5;
vector <int> g[nmax];
bitset <nmax> viz;

void dfs(int dad) {
    viz[dad]=true;
    for(auto son : g[dad])
        if(viz[son]==false) dfs(son);
}

int main() {
    ios_base::sync_with_stdio(false);
    int n, m, i, x, y, comp=0;
    fin >> n >> m;
    for(i=1; i<=m; i++) {
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(i=1; i<=n; i++) {
        if(viz[i]==false) {
            comp++;
            dfs(i);
        }
    }
    fout << comp << "\n";
    fin.close();
    fout.close();
    return 0;
}