#include <fstream>
#include <vector>

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

vector <int> G[100005];
bool v[100005];
int insule = 0;
void dfs(int k)
{
    v[k] = 1;
    for (unsigned int i=0; i<G[k].size(); i++)
    {
        int vecin = G[k][i];
        if(v[vecin] == 0)
        {
            dfs(vecin);
        }
    }
}
int main()
{
    int n, m;
    fin >> n >> m;
    for (int i=0; i<m; i++)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout << insule << " ";
    return 0;
}