#include <fstream>
#include <vector>
#define nmax 100005

using namespace std;

int n,m;
vector <int> g[nmax];
bool viz[nmax];

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

void citire()
{
    int x,y;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void dfs(int k)
{
    viz[k] = true;
    for(vector<int> :: iterator ii = g[k].begin();ii!=g[k].end();++ii)
        if(!viz[*ii])
            dfs(*ii);
}

void rezolv()
{
    int nr=0;
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr<<"\n";
}

int main()
{
    citire();
    rezolv();
    return 0;
}