#include<fstream>
#include<vector>
using namespace std;
int n,m,viz[100010],sol;
vector <int> v[100010];
void citire(){

    ifstream in("dfs.in");
    int i,x,y;
    in>>n>>m;
    for(i=1;i<=m;i++){
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    in.close();

}

void dfs(int nod){

    int vecin,i;
    viz[nod]=1;
    for(i=0;i<v[nod].size();i++){
        vecin=v[nod][i];
        if(viz[vecin]==0)
            dfs(vecin);
    }

}


void solve(){
    int i;
    for(i=1;i<=n;i++)
        if(viz[i]==0){
        sol++;
        dfs(i);
        }
}

void afisare (){

    ofstream out("dfs.out");
    out<<sol<<'\n';
    out.close();

}

int main() {
    citire();
    solve();
    afisare();
    return 0;
}