#include<bits/stdc++.h>
#define dim 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
 bitset<dim> fr;
 vector <int> L[dim];
 int n,m,i,sol,x,y;
 void dfs(int nod){
 fr[nod]=1;
 for(auto it:L[nod]){
    if(fr[it]==0)
        dfs(it);
 }
 }
 int main(){
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1;i<=n;i++){
        if(fr[i]==0){
            dfs(i);
            sol++;
        }
    }
    fout<<sol;

 }