#include <fstream>
#include <vector>
#include <string.h>

using namespace std;
const int Nmax = 100005;

vector<int> G[Nmax];
int used[Nmax];
int component = 0;

void dfs(int a)
{
    used[a] = component;
    for (auto x: G[a])
    {
        if (!used[x])
            dfs(x);
    }
}

int main()
{
    ifstream f ("dfs.in");
    ofstream g ("dfs.out");

    memset(used, 0, sizeof(used));
    int N, M, a, b;
    f >> N >> M;
    for (int i = 0; i < M; i++)
    {
        f >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    for (int i = 1; i <= N; i++)
    {
        if (!used[i])
        {
            component++;
            dfs(i);
        }
    }
    g << component << '\n';

    return 0;
}