#include <fstream>
#include <vector>
#include <queue>
using namespace std;
queue <int> coada;
vector <int> graf[100002];
int d[100002];
int main()
{
    int n,m,i,j,nr,nod,a,b;
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>a>>b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    nr=0;
    for(i=1;i<=n;i++)
    {
        if(d[i]==0)
        {
            d[i]=1;
            nr++;
            coada.push(i);
            while(!coada.empty())
            {
                nod=coada.front();
                coada.pop();
                for(j=0;j<graf[nod].size();j++)
                {
                    if(d[graf[nod][j]]==0)
                    {
                        d[graf[nod][j]]=d[nod]+1;
                        coada.push(graf[nod][j]);
                    }
                }
            }
        }
    }
    out<<nr;
    return 0;
}