#include <fstream>
#include <vector>
#define DIM 100002
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,sol,viz[DIM];
vector <int> v[DIM];
void DFS(int x){
    viz[x]=1;
    for(int i=0;i<v[x].size();i++)
        if(!viz[v[x][i]])
            DFS(v[x][i]);

}
int main(){
    fin>>n>>m;
    while(m--){
        int x,y;
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i]){
            sol++;
            DFS(i);
        }
    fout<<sol;
    fin.close();fout.close();
    return 0;
}