#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

vector <int> noduri[100005];
int vizitat[100005];

void dfs(int nod)
{
    for(auto it : noduri[nod])
    {
        if(!vizitat[it])
        {
            vizitat[it]=1;
            dfs(it);
        }
    }
}
int main()
{
    int n,m,i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        noduri[x].push_back(y);
        noduri[y].push_back(x);
    }
    int cnt=0;
    for(i=1;i<=n;i++)
    {
        if(!vizitat[i])
        {
            dfs(i);
            cnt++;
        }
    }
    fout<<cnt;
    /** for(auto i=0;i<noduri[1].size();i++) ===== for(auto it : noduri[nod])
        cout<<noduri[1][i];              */
    return 0;
}