#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int N, M, x, y, sol;
vector <int> G[100005];
bitset < 100005 > viz;

void dfs(int nod)
{
    viz[nod]=1;
    vector <int>::iterator it=G[nod].begin();
    for (; it!=G[nod].end(); ++it)
        if (!viz[*it]) dfs(*it);
}

int main()
{
    f>>N>>M;
    for (int i=1; i<=M; ++i)
    {
        f>>x>>y;
        G[x].emplace_back(y);
        G[y].emplace_back(x);
    }

    for (int i=1; i<=N; ++i)
        if (!viz[i])
            ++sol, dfs(i);

    g<<sol<<'\n';
    return 0;
}