//
//  main.cpp
//  dfs+
//
//  Created by Catalina Brinza on 12/10/13.
//  Copyright (c) 2013 Catalina Brinza. All rights reserved.
//

#include <fstream>
#include <vector>
#include <queue>
#define nr 100001
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int main()
{vector <int> v[nr];
    queue <int> q;
    bool viz[nr];
    int n,m,i,x,y,ji,k;
    f>>n>>m;
    for (i=0;i<m;++i)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
        viz[x]=false;
        viz[y]=false;
    }
    int nru=0;
    for (k=0;k<n;++k)
    {
        if (!viz[k])
        {
            ++nru;
            viz[k]=true;
            q.push(k);
            while (!q.empty())
            {
                i=q.front();
                for (ji=0;ji<v[i].size();++ji)
            {
                if (!viz[v[i][ji]]) {q.push(v[i][ji]); viz[v[i][ji]]=true;}
            }
                q.pop();
            }
        }
    }
    g<<nru;
    g.close();
    f.close();
    return 0;
}