#include <fstream>
#include <vector>

using namespace std;

int n,m;
bool parcurs[100000];
vector <int> adiacenta[100000];

inline void citire()
{
    ifstream f("dfs.in");
    f>>n>>m;
    int x,y;
    for(int i=0;i<m;++i)
    {
        f>>x>>y;
        --x;--y;
        adiacenta[x].push_back(y);
        adiacenta[y].push_back(x);
    }
    f.close();
}

void dfs(int nod)
{
    parcurs[nod]=1;
    for(unsigned int i=0;i<adiacenta[nod].size();++i)
        if(parcurs[adiacenta[nod][i]] == 0)
        {
            dfs(adiacenta[nod][i]);
        }
}

int main()
{
    int conexe = 0;
    citire();
    for(int i=0;i<n;++i)
    {
        if(parcurs[i] == 0)
        {
            ++conexe;
            dfs(i);
        }
    }
    ofstream g("dfs.out");
    g<<conexe;
    g.close();
    return 0;
}