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


using namespace std;

bool viz[100005];
int rez=0;
vector <int> lista[100005];
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<lista[nod].size();++i)
    {
        int nod2=lista[nod][i];
        if(viz[nod2]==0)
        {
            dfs(nod2);
        }


    }
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int n,m,x,y;
    f >> n >> m;
    for(int i=1;i<=m;++i)
    {
        f >> x >> y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
    {
        if (viz[i]==0)
            {
                rez++;
                dfs(i);
            }
    }
    g << rez;

    return 0;
}