#include <fstream>
#include <vector>

using namespace std;
#define nMAX 100005

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

int n,m,sol=0;
vector <int> noduri[nMAX];
bool viz[nMAX];
void DFS(int nod)
{
    viz[nod]=true;
    for(unsigned int i=0;i<noduri[nod].size();i++)
    {
        int k=noduri[nod][i];
        if(!viz[k])
            DFS(k);
    }
}
int main()
{   int x,y;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        noduri[y].push_back(x);
        noduri[x].push_back(y);
    }
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            sol++;
            DFS(i);
        }
    }
    fout<<sol;

}