#include <iostream>
#include <fstream>
#include <list>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
list <int>v[100005];

bool verif[100005];
int nr,n,m,x,y,i;

void dfs(int k){
    int kk;
    verif[k]=1;
    list <int> :: iterator it;
    for(it=v[k].begin();it!=v[k].end();++it)
    {
        kk=*it;
        if(verif[kk]==0) dfs(kk);
    }
}


int main()
{
    in>>n>>m;
    for(i=1;i<=m;i++){
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
     for(i=1;i<=n;++i)
        if(verif[i]==0){
            dfs(i);
            ++nr;
        }
        out<<nr;


        /*for(int k=1;k<=n;k++){
             for(it=v[k].begin();it!=v[k].end();++it)
    {
        out<<*it<<' ';
    } out<<endl;
        }*/

    return 0;
}