#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

int viz[100005];
vector <int> graph[100005];
void dfs(int node)
{
    viz[node]=1;
    int lim=graph[node].size();
    for(int i=0; i<lim; i++)
    {
        int vecin=graph[node][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    int nr=0;
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    int noduri,muchii;
    fin>>noduri;
    fin>>muchii;
    int x,y;
    for(int i=1;i<=muchii;i++)
    {
        fin>>x;
        fin>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i=1;i<=noduri;i++)
        if(!viz[i])
        {
            dfs(i);
            nr++;
        }
    fout<<nr;
}