#include <fstream>
#include<vector>
#include <queue>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<vector<int>>galeata;
vector<bool>folosit;
queue<int>q;
void  bfs(int nod){
    folosit[nod]=true;
    q.push(nod);
    while(!q.empty()){
        int nodCurent=q.front();
        q.pop();
        for(auto&vecin:galeata[nodCurent]){
            if(!folosit[vecin]){
                folosit[vecin]=true;
                q.push(vecin);
            }
        }
    }

}
int main()
{
    int n,m;
    cin>>n>>m;
    galeata.resize(n+1);
    folosit.resize(n+1,false);
    while(m--){
        int a,b;
        cin>>a>>b;
        galeata[a].push_back(b);
        galeata[b].push_back(a);
    }
    int compConex=0;
    for(int i=1;i<=n;i++){
        if(!folosit[i]){
            compConex++;
            bfs(i);
        }
    }
    cout<<compConex<<" ";
    return 0;
}