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