#include <fstream>
#include <vector>
using namespace std;
vector <int> v[100001];
int n,m,i,nr,viz[100002],q[100001],x,y;
void coada(int x){
    int l,i,p,u;
    p=u=1;
    q[p]=x;
    while(p<=u){
        l=q[p];
        p++;
        for(i=0;i<v[l].size();i++){
            if(viz[v[l][i]]==0){
                viz[v[l][i]]=1;
                u++;
                q[u]=v[l][i];
            }
        }
    }
}
int main()
{
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    cin>>n>>m;
    for(i=1;i<=m;i++){
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    nr=0;
    for(i=1;i<=n;i++)
        if(viz[i]==0){
            nr++;
            viz[i]=1;
            coada(i);
        }
    cout<<nr;
    return 0;
}