#include <fstream>
#include <vector>
#define Nmax 100001
using namespace std;
vector <int> G[Nmax];
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m;
bool ap[Nmax];
void DFS(int i){
    for (auto j:G[i])
    {
        if (ap[j]==0)
        {
            ap[j]=1;
            DFS(j);
        }
    }
}
int main()
{
    int a,b,i;
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        fin>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    int nr=0;
    for (i=1;i<=n;i++)
    {
        if (ap[i]==0)
            {
                nr++;
                DFS(i);
            }
    }
    fout<<nr;
    return 0;
}