#include <fstream>
#include <vector>
using namespace std;
ofstream fout("dfs.out");
ifstream fin("dfs.in");
const int NMAX = 100001;

int n, m, s, nr;
int viz[NMAX];
vector<int> v[NMAX];

void citire()
{
    int x, y;

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

void dfs(int nod)
{
    viz[nod] = nr;
    for(unsigned int i=0; i<v[nod].size(); i++) {
         if(!viz[v[nod][i]])
             dfs(v[nod][i]);
    }
}

int main()
{
    citire();
    for(int i=1; i<=n; i++) if(!viz[i]) { ++nr; dfs(i); }
    fout << nr << '\n';

    fin.close();
    fout.close();
    return 0;
}