#include <fstream>
#include <deque>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> v[100001];
deque <int> coada;
bool  viz[100001];
void bfs(int start)
{
    coada.push_back(start);
    viz[start] = 1;
    while(!coada.empty())
    {
        int nod = coada.front();
        //g << nod << ' ';
        for(int i = 0; i<v[nod].size(); ++i)
            if(!viz[v[nod][i]])
        {
            coada.push_back(v[nod][i]);
            viz[v[nod][i]] = 1;
        }
        coada.pop_front();
    }
}
int main()
{
   int n, m;
   f >> n >> m;
   for(int i = 1; i<=m; i++)
{

       int x, y;
       f >> x  >> y;
            v[x].push_back(y);
        v[y].push_back(x);
}


   int nr = 0;
   for(int i = 1; i<=n; i++)
   {
       if(!viz[i])
       {
           nr ++;
           bfs(i);
       }
   }
   g << nr;
   return 0;
}