#include <fstream>
#include <vector>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,a,b;
vector <int> V[100005];
bool checked[100011];
void dfs(int x)
{
    checked[x]=1;
    vector <int>::iterator it;
    for (auto &it:V[x])
        if (!checked[it]) dfs(it);

}


int main()
{
    fin>>n>>m;
    int nr=0;
    for (int i=1; i<=m; ++i)
    {
        fin>>a>>b;
        V[a].push_back(b);
        V[b].push_back(a);

    }

   for(int i=1; i<=n; ++i)
    if (checked[i]==false)
    nr++,dfs(i);

    fout<<nr;
    return 0;

}