#include <vector>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> v[100005];
int n, m, x, y, cont;
int check[100005];
void mark(int nod)
{
    check[nod] = 1;
    for (int j = 0; j < v[nod].size(); ++j)
    {
        if (!check[v[nod][j]])
            mark(v[nod][j]);
    }
}
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 (!check[i])
        {
            cont++;
            mark(i);
        }
    }
    g << cont;
    return 0;
}