#include <iostream>
#include<bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int viz[100000],n,m,cont;
vector <int> v[100000];
void dfs(int nod)
{

    viz[nod]=1;
    for(auto i:v[nod])
        if(!viz[i])dfs(i);
}
int main()
{
   int x,y,i;
   f>>n>>m;
   for(i=1;i<=m;i++)
   {f>>x>>y;
       v[x].push_back(y);
       v[y].push_back(x);

   }
   for(i=1;i<=n;i++)
   {
       if(viz[i]==0){
        cont++;
        dfs(i);

    }
   }
   g<<cont;
   return 0;
}