#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in"); ofstream fout("dfs.out");
int n,m;
vector<int> a[100001]; int ct;
bool skibidi[100001];


void dfs(int node){
    skibidi[node]=1;
    for(auto neighbour:a[node])
        if(!skibidi[neighbour]) dfs(neighbour);


}
int main()
{
   fin>>n>>m;
   for(int i=1; i<=m; i++){
    int x,y; fin>>x>>y;
    a[x].push_back(y);
    a[y].push_back(x);
   }
   for(int i=1; i<=n; i++){
    if(skibidi[i]==0){
        ct++; dfs(i);
    }
   }
   fout<<ct;
}