#include <fstream>
#include <vector>

using namespace std;

struct nod
{
    vector <int> vec;
};

ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, ans = 0;
nod v[100005];
int viz[100005];

void dfs(int k)
{
    viz[k] = 1;

    for(int i = 0; i<v[k].vec.size(); i++)
    {
        if(viz[v[k].vec[i]] == 0)
        {
            dfs(v[k].vec[i]);
        }
    }

}

int main()
{
    f>>n>>m;
    int st, dr;
    for(int i = 1; i<=m; i++)
    {
        f>>st>>dr;
        v[st].vec.push_back(dr);
        v[dr].vec.push_back(st);
    }

    for(int i = 1; i<=n; i++)
    {
        if(viz[i] == 0)
        {
            ans++;
            dfs(i);
        }
    }

    g<<ans;

    return 0;

}