#include <fstream>
#include <vector>
#include <bitset>

using namespace std;

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

vector <int> L[100005];
bitset <100005> viz;

int n, m;

void Read ()
{
    fin >> n >> m;
    int i, j;
    while (m--)
    {
        fin >> i >> j;
        L[i].push_back(j);
        L[j].push_back(i);
    }
}

void DFS (int x)
{
    viz[x] = 1;
    for (auto i : L[x])
        if (!viz[i]) DFS(i);
}

void Write ()
{
    int i, comp = 0;
    for (i = 1; i <= n; i++)
        if (!viz[i])
        {
            comp++;
            DFS(i);
        }
    fout << comp << "\n";
    fout.close();
}

int main()
{
    Read();
    Write();
    return 0;
}