#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f ("dfs.in");
ofstream g ("dfs.out");
vector<int>adiacenta[100001];
int n,m,cnt;
bool viz[100001];
queue<int>q;
void DFS(int nod)
{
    viz[nod] = 1;
    for(auto x:adiacenta[nod])
    {
        if(!viz[x])
        {
            DFS(x);
        }
    }
}
int main()
{
    f >> n >> m;
    for(int i = 1;i<=m;i++)
    {
        int x,y;
        f >> x >> y;
        adiacenta[x].push_back(y);
        adiacenta[y].push_back(x);
    }
    for(int i =1;i<=n;i++)
    {
        if(!viz[i]){
            DFS(i);
            cnt++;
        }
    }
    g << cnt;

}