#include <fstream>
#include <vector>
using namespace std;
vector<int>g[100005];

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

int drum, nod,x,y,viz[100005],nr;

void recursiv(int x)
{
    viz[x]=1;
    for (auto &v:g[x])
    {
        if (viz[v]==0)
            recursiv(v);
    }
}

int main()
{
    fin >> nod >> drum;
    for (int i=0; i<drum; i++)
    {
        fin>> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for (int i=1; i<=nod; i++)
    {
        if (viz[i]==0)
        {
            nr++;
            recursiv(i);}
    }
    fout << nr;
    return 0;
}