#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
vector <int> lv[100110];
int viz[100110];

int DFS(int x)
{
    if(!viz[x])
    {
        viz[x] = 1;
        int n = lv[x].size();
        for(int i=0;i<n;i++)
        {
            DFS(lv[x][i]);
        }
        
    
    }
    
    return 0;
}
int main()
{
    int n, m;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    
    cin>>n>>m;
    int x,y;
    for (int i=1;i<=m;i++)
    {    
        cin>>x>>y;
        lv[x].push_back(y);
        lv[y].push_back(x);
    }
    
    int componente = 0;
    for(int i=1;i<=n;i++)
    {
        if(!viz[i]) 
            DFS(i),componente++;
    }
    
    cout<< componente;
    return 0;
}