#include <iostream>
#include <vector>
#include <fstream>
std::ifstream fin("dfs.in");
std::ofstream fout("dfs.out");
std::vector <int> graf[100010];
int viz[100010];


void dfs(int node)
{
    viz[node]=1;

    for(unsigned int i=0;i<graf[node].size();i++)
    {
        if( ! viz[graf[node][i]])
            dfs(graf[node][i]);
    }
}


int main()
{
    int x,y,noduri,muchii,nr=0;
    fin>>noduri>>muchii;

    for(unsigned int i=0;i<muchii;i++)
    {
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    for(unsigned int i=1;i<=noduri;i++)
    {
      if(!viz[i])
        nr+=1;
        dfs(i);
    }

    fout<<nr;

}