#include <fstream>
#include <vector>
#define NMAX 100010
#define pb push_back
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> G[NMAX];
int i,n,m,x,y,nr;
bool sel[NMAX];
void dfs(int nod){
    int i;
    sel[nod]=true;
    for(i=0;i<G[nod].size();i++)
        if(!sel[G[nod][i]])
            dfs(G[nod][i]);

}

int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++){
        f>>x>>y;
        G[x].pb(y);
        G[y].pb(x);
    }
    for(i=1;i<=n;i++)
        if(!sel[i]){
            nr++;
            dfs(i);
        }
    g<<nr<<'\n';
    return 0;
}