#include <fstream>
#include <vector>
using namespace std;

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

bool vis[200005];
int /*vertex[200005],*/ x, y, m, n;

vector <int> V[200005];

void DFS (int nod)
{
    vis[nod] = true;
     for (int i = 0; i < V[nod].size(); ++i)
     {
         int neighbour = V[nod][i];
         if (vis[neighbour] == false)
         {
             DFS(neighbour);
         }
     }
}

int main()
{
    f >> n >> m;

    int i, nr = 0;
    for (i = 0; i < m; ++i)
    {
        f >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }

    for (i = 0; i < n; ++i)
    {
        if(vis[i] == false)
        {
            ++nr;
            DFS(i);
        }
    }

    g << nr;
    return 0;
}