#include<fstream>
#include<vector>
using namespace std;
vector <int> V[100005];
int n,i,cate,m,x,y,viz[100005];
void df(int v){
    int i;
    viz[v]=1;
    for(i=0;i<V[v].size();i++)
        if(viz[V[v][i]]==0)
            df(V[v][i]);
}
int main(){
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0){
            cate++;
            df(i);
        }
    fout<<cate<<'\n';
    fin.close();
    fout.close();
}