#include <fstream>
#include <vector>

using namespace std;

int n, m, v[100005];
vector < int > L[100005];

void DFS(int vertex)
{
    v[vertex] = 1;
    for(auto w : L[vertex])
        if(!v[w])
            DFS(w);
}

int main()
{
    int x, y, nrc = 0;
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    fin.close();
    for(int i = 1; i <= n; i++)
        if(!v[i])
        {
            nrc++;
            DFS(i);
        }
    fout << nrc << "\n";
    fout.close();
    return 0;
}