#include <fstream>
#include <vector>

using namespace std;

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

int n, m, x, y;
bool u[100001];
vector < int > v[100001];

void dfs(int nod)
{
    u[nod] = 1;
    for (int i=0; i<v[nod].size(); i++)
        if (!u[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);
    }

    int nrComp = 0;
    for (int i=1; i<=n; i++)
        if (!u[i])
        {
            nrComp++;
            dfs(i);
        }

    g << nrComp;

    return 0;
}