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

using namespace std;

#define maxN 100005

vector <int> list[maxN];
bool Viz[maxN];


void DFS(int nod) {
    Viz[nod] = true;

    for(int i = 0; i < list[nod].size(); ++ i) {
        int nod2 = list[nod][i];

        if(Viz[nod2]) continue;
        DFS(nod2);
    }
}

int main() {
    ifstream f("dfs.in");
    ofstream g("dfs.out");

    int N, M;
    f >> N >> M;

    while(M --) {
        int x, y;
        f >> x >> y;

        list[x].push_back(y);
        list[y].push_back(x);
    }

    int nrCC = 0;
    for(int i = 1; i <= N; ++ i) {
        if (Viz[i]) continue;

        nrCC ++;
        DFS(i);
    }

    g << nrCC;

    return 0;
}