#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream fi("dfs.in");
ofstream fo("dfs.out");

int viz[100050];

vector <long int> G[100050];

long int nr,n,m;



void dfs(long int nod)
{
    viz[nod]=1;

    for(long int i=0;i<G[nod].size();i++)
        if(!viz[G[nod][i]])
            dfs(G[nod][i]);

}




int main()
{
    fi>>n>>m;

    for(long int i=0;i<m;i++)
    {
        long int x,y;

        fi>>x>>y;

        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(long int i=1;i<=n;i++)
        if(!viz[i])
            {nr++;
            dfs(i);}

    fo<<nr;

    return 0;
}