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

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

using VI = vector <int>;
using VVI = vector <VI>;

VVI G;

bool v[100005];

void DFS(int x);
void Read();

int n, m;

int main()
{
    int cnt = 0;
    Read();

    for (int i = 1; i <= n; ++i)
        if (!v[i])
        {
            ++cnt;
            DFS(i);
        }

    fout << cnt;
}

void Read()
{
    int x, y;
    fin >> n >> m;

    G = VVI(n + 1);

    for (int i = 1; i <= m; ++i)
    {
        fin >> x >> y;
        G[x].emplace_back(y);
        G[y].emplace_back(x);
    }
}

void DFS(int x)
{
    v[x] = true;
    for (auto y : G[x])
    {
        if (v[y]) continue;
        DFS(y);
    }
}