#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,cc;
bool viz[100005];
vector <int> muchii[100005];
void dfs(int nod)
{
    viz[nod]=true;
    for (unsigned int i=0;i<muchii[nod].size();i++)
    {
        int vecin=muchii[nod][i];
        if (!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    fin >> n >> m;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (int i=1;i<=n;i++)
    {
        if (!viz[i])
        {
            cc++;
            dfs(i);
        }
    }
    fout << cc;
}