#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, viz[100010], nr;
queue<int>Q;
vector<int>graf[100010];
void citire()
{
    f>>n>>m;
    int x, y;
    for(int i=0; i<m; i++)
    {
        f>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
}
void parcurgere(int x)
{
    viz[x]=1;
    for(auto &v:graf[x])
        if(viz[v]==0)
            parcurgere(v);
}
int main()
{
    citire();
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            nr++;
            parcurgere(i);
        }
    g<<nr;
    return 0;
}