# include <fstream>
# include <vector>
# define DIM 100010
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int Marcat[DIM],n,m,x,y,i,nr;
vector <int> Lista[DIM];
void dfs(int nod){
    int i,j;
    Marcat[nod]=1;
    for(i=0;i<Lista[nod].size();i++){
        j=Lista[nod][i];
        if(Marcat[j]==0)
            dfs(j);
    }
    return;
}
int main () {
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        Lista[x].push_back(y);
        Lista[y].push_back(x);
    }
    for(i=1;i<=n;i++){
        if(Marcat[i]==0){
            nr++;
            dfs(i);
        }
    }
    fout<<nr<<"\n";
    return 0;
}