#include <fstream>
#include <vector>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> v[50010];

int n,m,x,y,viz[50010],numar_componente;
void DFS(int);
int main()
{
    f>>n>>m;
    for(;m;m--)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            numar_componente++;
            DFS(i);
        }
    g<<numar_componente<<"\n";
    return 0;
}
void DFS(int nod)
{
    viz[nod]=1;
    for(auto vecin:v[nod])
        DFS(vecin);
}