#include <fstream>
#include <vector>

using namespace std;

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

int n, m;
bool verificare[100005];

vector <int>vectorr[100005];

void citire(){
    fin >> n >> m;
    int x, y;
    for (int i=1; i<=m; i++){
        fin >> x >> y;
        vectorr[x].push_back(y);
        vectorr[y].push_back(x);
    }
}

void dfs(int x){
    verificare[x]=1;
    for(auto &a: vectorr[x])
        if(!verificare[a])
            dfs(a);
}

void rezolvare(){
    int contor=0;
    for(int i=1; i<=n; i++)
        if(!verificare[i]){
            contor++;
            dfs(i);
        }
    fout << contor;
}

int main()
{
    citire();
    rezolvare();
    return 0;
}