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

#define N 100001

vector <int> v[N];
int vizitat[N];

void dfs (int node)
{
    vizitat[node] = 1;
    int n = v[node].size ();
    for (int i=0; i<n; i++){
        int now = v[node][i];
        if (vizitat[now] == 0){
            dfs(now);
        }
    }
}

int main ()
{
    ifstream in ("dfs.in");
    ofstream out ("dfs.out");
    int n, m, ct = 0;
    in >> n >> m;
    for (int i=1; i<=m; i++){
        int x, y;
        in >> x >> y;
        v[x].push_back (y);
        v[y].push_back (x);
    }

    for (int i=1; i<=n; i++){
        if (vizitat[i] == 0){
            ct ++;
            dfs (i);
        }
    }

    out << ct;

    return 0;
}