#include <iostream>
#include<fstream>
#include<vector>
#define mx 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m;
bool viz[mx];
vector<int> v[mx];
void citire()
{
    int i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void dfs(int nod)
{
    viz[nod]=true;
    for(unsigned int i=0;i<v[nod].size();++i)
        if(viz[v[nod][i]]==false)
        dfs(v[nod][i]);
}
int main()
{
    int i,nr=0;
    citire();
    for(i=1;i<=n;i++)
        if(!viz[i])
    {
        nr++;
        dfs(i);
    }
    fout<<nr;
    return 0;
}