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