#include <fstream>
#include <vector>

using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int m,n;
vector<vector<int>> adj;
vector<int> viz;

void DFS(int nod){
    viz[nod]=1;
    for(int vecin : adj[nod])
    {
        if (!viz[vecin])
        {
            DFS(vecin);
        }
    }

}
int main()
{
    fin>>n>>m;
    adj.resize(n+5);
    viz.resize(n+5,0);
    for(int i=1;i<=m;i++)
    { int x,y;
    fin>>x>>y;
    adj[x].push_back(y);
    adj[y].push_back(x);

    }
    int cnt_comp=0;
    for(int i=1;i<=n;i++)
    {if(!viz[i]){
        cnt_comp++;
        DFS(i);
    }
    }
    fout<<cnt_comp<<"\n";

    return 0;
}