#include <iostream>
#include<vector>
#include<fstream>
using namespace std;
int viz[100005];
vector<int>graph[100005];
void DFS(int nod)
{
    viz[nod]=1;
    int lim=graph[nod].size();
    for(int i=0;i<lim;i++)
    {
        int vecin=graph[nod][i];
        if(!viz[vecin])
            DFS(vecin);
    }

}
int main()
{   ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n,m,a,b,i,nr=0;

    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>a>>b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            DFS(i);
            nr++;
        }
    }
    out<<nr;

    return 0;
}