#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define nmax 100005
int nr=0, n, m;
bool viz[nmax]={0};
vector<int> g[nmax];
void citire()
{
    int i, x, y;
    fin>>n>>m;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    fin.close();
}
void dfs(int nod)
{
    vector<int>::iterator it;
    viz[nod]=1;
    for(it=g[nod].begin(); it!=g[nod].end(); it++)
        if(!viz[*it])
            dfs(*it);
}
void solve()
{
    int i;
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    fout<<nr;
    fout<<'\n'; fout.close();
}
int main()
{
    citire();
    solve();
    return 0;
}