#include <fstream>
#include <vector>
#define nmax 100005

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, nr;
vector<int>G[nmax]; ///G[i]= lista de adiacenta a vf i
bool viz[nmax];
void citire();
void dfs(int x);
int main()
{
    int i;
    citire();
    for (i=1; i<=n; i++)
        if (viz[i]==0)
    {
        nr++;
        dfs(i);
    }
    fout<<nr<<'\n';
    return 0;
}
void citire()
{
    int k, i, j;
    fin>>n>>m;
    for (k=0; k<m; k++)
    {
        fin>>i>>j;
        G[i].push_back(j);
        G[j].push_back(i);
    }
}
void dfs(int x)
{
    int i;
    viz[x]=1;
    for (i=0; i<G[x].size(); i++)
        if (viz[G[x][i]]==0)
            dfs(G[x][i]);
}