#include <fstream>
#include <vector>
#define NMAX 100002
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,nr;
vector<int> G[NMAX]; ///G[i] lista de adiacenta a varfului i
bool viz[NMAX];
void citire();
void dfs(int);
int main()
{
    citire();
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    fout<<nr;
    return 0;
}
void citire()
{
    int m,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]);
}