//#include <iostream>
#include <vector>
#include <fstream>
using namespace std;

ofstream cout("dfs.out");
ifstream cin("dfs.in");

vector<int> v[100005];
bool fol[100005];
void dfs(int nod){
    for(int i=0;i<v[nod].size();i++){
        if(fol[v[nod][i]]==false){
            fol[v[nod][i]]=true;
            dfs(v[nod][i]);
        }
    }
}
int main()
{
    int n,m,a,b,cnt=0;
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;i++){
        if(fol[i]==false){
            fol[i]=true;
            dfs(i);
            cnt++;
        }
    }
    cout<<cnt;
    return 0;
}