#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream F("dfs.in");
ofstream G("dfs.out");
int n,m,i,x,y,viz[100005],nrinsule;
vector <int> muchii[100005];
void DFS(int nod)
{
    viz[nod]=1;
    for(unsigned int i=0;i<muchii[nod].size();++i)
    {
        int vecin=muchii[nod][i];
        if(viz[vecin]==0)
        {
            DFS(vecin);
        }
    }
}
int main ()
{
   F>>n>>m;
    for(i=1;i<=m;++i)
    {
        F>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nrinsule++;
            DFS(i);
        }
    }
    G<<nrinsule;
    return 0;
}