#include <fstream>
#include <vector>

const int NMAX = 100005;

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,count,x,y;
bool used[NMAX];
vector <int> v[NMAX];

void DFS(int nod)
{
    used[nod] = true;
    for (int i = 0; i < v[nod].size(); ++i)
    {
        if (!used[v[nod][i]])
            DFS(v[nod][i]);
    }
}

int main()
{
    f >> n >> m;
    for (int i = 1; i <= m ; ++i)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!used[i])
        {
            count++;
            DFS(i);
        }
    }
    g << count;
    return 0;
}