#include <iostream>
#include <bits/stdc++.h>

using namespace std;

ifstream in ("dfs.in");
ofstream out ("dfs.out");
int n,m;
vector <int> muchii[100005];
int vizitat[100005];
void dfs(int nod){
    vizitat[nod]=true;
    for(unsigned int i=0;i<muchii[nod].size();i++){
        int vecin =muchii[nod][i];
        if(vizitat[vecin]==0){
            dfs(vecin);
        }
    }
}
int main()
{
    in>>n>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        in>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    int contor=0;
    for(int i=1;i<=n;i++){
        if(vizitat[i]==0){
            dfs(i);
            contor++;
        }
    }
    out<<contor;
    return 0;
}