#include <iostream>
#include <fstream>
#define Nmax 100001
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> G[Nmax];
int viz[Nmax];
void DFS(int nod)
{
   int i;
    viz[nod]=1;
    for(i=0;i<G[nod].size();i++)
        if(!viz[G[nod][i]])
            DFS(G[nod][i]);
}

int main()
{
    int n,m,comp_conex=0;
    fin>>n>>m;
    int i,x,y;
    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])
            comp_conex++,DFS(i);


    fout<<comp_conex<<"\n";

    return 0;
}