#include <fstream>
#include <vector>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector <int> G[100005];

bool viz[100005];

int n,m;

void dfs(int poz)
{
    viz[poz]=1;
    for(int i=0;i<G[poz].size();i++)
    if(viz[G[poz][i]]==0)
        dfs(G[poz][i]);
}

int parcurge()
{
    int total=0;
    for(int i=1;i<=n;i++)
    if(viz[i]==0)
    {
        total++;
        dfs(i);
    }
    return total;
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        fin>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    fout << parcurge();
    return 0;
}