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

const int NMAX = 100005;
vector <int> graf[NMAX];
bool fr[NMAX];
int n, m, cnt;
queue <int> coada;

void dfs(int i){

    coada.push(i);
    fr[i] = true;

    while(coada.empty() == false){
        int nod = coada.front();
        coada.pop();

        for(size_t i = 0; i < graf[nod].size(); ++i){
            if(fr[graf[nod][i]] == false){
                fr[graf[nod][i]] = true;
                coada.push(graf[nod][i]);
            }
        }
    }
}

int main() {
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;

    for (int i = 1; i <= m; ++i){
        int a, b;
        fin >> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }

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

    fout << cnt;

    return 0;
}