#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
const int N = 1e5 + 1;
int n, m, cnt;
bool viz[N];
vector <int> a[N];//a[0] e un vector, a[1] e un vector...
void citire ()
{
    fin >> n >> m;
    while (m --)
    {
        int x, y;
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}
void dfs (int nod)
{
    viz[nod] = true;
    for (auto y: a[nod]){
        if(!viz[y])
            dfs(y);
    }
}
int main()
{
    citire();
    for (int i=1; i<=n; i++)
        if (!viz[i]){
            cnt++;
            dfs(i);
        }
    fout << cnt;
    return 0;
}