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

const int n_max = 100005;
int m, n, viz[n_max];
vector <int> v[n_max];
vector <int> :: iterator it;

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

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

void bfs(int nod)
{
    viz[nod] = 1; //d = vizitat
    for(it=v[nod].begin(); it<=v[nod].end(); ++it)
        if(viz[*it] == 0)
        {
            viz[*it] = 1;
            bfs(*it);
        }
}

int main()
{
    citire();
    int contor = 0;
    for(int i=1;i<=n;++i)
        if(viz[i] == 0)
        {
            contor++;
            bfs(i);
        }

    fout<<contor;

    return 0;
}