#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in ("dfs.in");
ofstream out("dfs.out");
int const N=100005;
bool marcat[N];
vector <int> a[N];
int n,m,cicluri;
void citire ()
{
    int x,y;
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}
void dfs (int x)
{
    marcat[x]=true;
    for(size_t i=0;i<a[x].size();i++)
        if(!marcat[a[x][i]])
            dfs(a[x][i]);
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(!marcat[i])
        {
            dfs(i);
            cicluri++;
        }
    out<<cicluri<<"\n";
    return 0;
}