#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int NMAX=100000;
bitset <NMAX+5>viz;
vector <int>G[NMAX+5];
void DFS(int nod)
{
    int i;
    viz[nod]=1;
    for(i=0;i<G[nod].size();i++)
    {
        if(viz[G[nod][i]]==0)
          DFS(G[nod][i]);
    }
}
int main()
{
   int nrc=0, i, x, y, n, m;
   fin>>n>>m;
   for(i=1;i<=m;i++)
   {
     fin>>x>>y;
     G[x].push_back(y);
     G[y].push_back(x);
   }
   for(i=1;i<=n;i++)
   {
       if(viz[i]==0)
       {
           nrc++;
           DFS(i);
       }
   }
   fout<<nrc<<"\n";
    return 0;
}