#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
int const NR=100005;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,cnt;
vector < int > muchii[NR];
bool vizitat[NR];
void dfs (int k){
    vizitat[k]=true;
    for(unsigned int i=0;i<muchii[k].size();i++)
        if(!vizitat[muchii[k][i]]) dfs (muchii[k][i]);}

void citire (){
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        fin>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);}
    for(int i=1;i<=n;i++)
        if (vizitat[i]==false)  {cnt++;dfs(i);}
    fout<<cnt<<"\n";}
int main(){ citire ();
return 0;}