#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector <vector<int> > gr;
vector <int> vizitat;
int c;
void DFS(int node)
{
    vizitat[node]=1;
    for(int i=0;i<gr[node].size();++i)
    {
        if(vizitat[gr[node][i]]==0) DFS(gr[node][i]);
    }
}
int main()
{
    int n,m,x,y;
    fin >> n >> m;
    gr.clear();
    gr.resize(n+1);
    vizitat.resize(n+1);
    for(int i=0;i<m;++i)
    {
        fin >> x >> y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
    {
        if(vizitat[i]==0)
        {
            DFS(i);
            ++c;
        }
    }
    fout << c;
    return 0;
}