#include <fstream>
#include <vector>
using namespace std;

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

int N,M,nr,i;
bool viz[100005];
vector <int> v[100005];


void citire()
{
    int x,y;

    fin>>N>>M;
    for(i=1;i<=M;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int nod)
{
    viz[nod]=1;
    for(vector <int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
    {
        if(!viz[*it])
            dfs(*it);
    }
}

int main()
{
    citire();

    for(i=1;i<=N;i++)
    {
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
    return 0;
}