#include<fstream>
#include<vector>

using namespace std;

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

vector < int > a[100001];
int i,n,m,x,y,nr;
int v[100001];
void dfs(int nod)
{
    v[nod]=1;
     for(int i=0;i<a[nod].size();i++)
        if(v[a[nod][i]]==0)
            dfs(a[nod][i]);

}
int main()
{
    in>>n>>m;
    for (i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);

    }
    for(i=1;i<=n;i++)
        if(v[i]==0)
            {
                nr++;
                dfs(i);
            }
    out<<nr;
    in.close();
    out.close();
    return 0;
}