#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

int N,M,viz[200006],cnt,a,b;
vector < int > adiacent[200006];

void dfsss(int nod)
{
    viz[nod]=1;
    for(int u=0;u<adiacent[nod].size();++u){
        if(viz[adiacent[nod][u]]==0)
        {
            dfsss(adiacent[nod][u]);
        }
    }

}

int main()
{
    cin>>N>>M;
    for(int i=1;i<=M;++i){
        f>>a>>b;
        adiacent[a].push_back(b);
        adiacent[b].push_back(a);
    }
    for(int i=1;i<=N;++i)
    {
        if(viz[i]==0)
        {
            dfsss(i);
            ++cnt;
        }
    }
    g<<cnt;
    return 0;
}