#include <fstream>
#include <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int> M[100005];

int n, m, nr, vect, x, y, viz[100005];

void citire()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        M[x].push_back(y);
        M[y].push_back(x);
    }
}

void dfs(int nod)
{
    viz[nod]=1;
    for(int i: M[nod])
    {
        vect=i;
        if(viz[vect]==0)
            dfs(vect);
    }
}

int numar()
{
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
        nr++;
        dfs(i);
        }
    }
    return nr;
}

int main()
{
    citire();
    fout<<numar();
    return 0;
}