#include<fstream>
#include<vector>
#include<bitset>
#define Nmax 100099
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,x,y,nr;
vector <int> G[Nmax];
bitset <Nmax> viz;
void DFS(int node){
    viz[node]=1;
    vector <int> :: iterator it;
    for(it=G[node].begin();it!=G[node].end();++it){
        if(viz[*it]==0) DFS(*it);
    }
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++){
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(viz[i]==0){
            DFS(i);
            ++nr;
        }
    }
    g<<nr<<'\n';
    f.close();g.close();
    return 0;
}