#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

vector < int > gr[100100];
bool used[100100];
queue < int > q;

int main()
{
    int n,m;
    in>>n>>m;

    for(int i=1;i<=m;i++){
        int x,y;
        in>>x>>y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }

    int cont=0;

    for(int s=1;s<=n;s++){
        if(used[s]){
            continue;
        }

        cont++;

        q.push(s);
        used[s]=true;

        while(!q.empty()){
            int nod;
            nod=q.front();
            q.pop();

            for(int i=0;i<gr[nod].size();i++){
                if(!used[gr[nod][i]]){
                    q.push(gr[nod][i]);
                    used[gr[nod][i]]=true;
                }
            }
        }
    }

    out<<cont;

    return 0;
}