#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
int n,m;
vector <int>a[100002];
int v[100002];
int cnt;
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 ()
{
    cin>>n>>m;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        cin>>x>>y;
        a[x].push_back(y),a[y].push_back(x);
    }
    for (int i=1;i<=n;i++)
    {
        if (v[i]==0)
        {
            DFS(i);
            cnt++;
        }
    }
    cout<<cnt;
}