#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#define dim 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> L[dim];
//bool fr[dim];
bitset<dim> fr;
int n,m,x,y;
void dfs(int nod){
    fr[nod]=1; /// marcam nodul vizitat
    for(int i=0;i<L[nod].size();i++){
        int vecin=L[nod][i];
        if(fr[vecin]==0)
            dfs(vecin);
    }
}
int main() {
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int nr=0;
    for(int i=1;i<=n;i++){
        /// trecem prin toate nodurile si vedem daca fac deja parte dintr-o insula deja vizitata
        if(fr[i]==0){
            /// nevizitata inca
            dfs(i);
            nr++;
        }
    }
    fout<<nr;
}