#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout ("dfs.out");
int n,m;
vector <vector <int> > a;
void cit()
{
    fin>>n>>m;
    int x,y;
    a.resize(n+1);
    for (int i=1;i<=m;i++)

    {   fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);

    }

}

bool viz[100001];
int k;
void DFS(int x)
{
    viz[x]=1;
    for(int vecin:a[x])
    {
        if(!viz[vecin])
            DFS(vecin);
    }

}
int main()
{
    cit();

    for(int i=1;i<=n;i++)
        if(viz[i]==0)
    {
        k++;
        DFS(i);
    }
    fout <<k;
    return 0;
}