#include <fstream>
#include <iostream>
#define NMAX 100005
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> contor[NMAX];
int N,M,i,nr=0,nod,x,y;
bool viz[NMAX];
void DFS(int nod)
{
    viz[nod]=true;
    for(int i=0;i<contor[nod].size();i++)
    {
        int next=contor[nod][i];
        if(!viz[next])
            DFS(next);
    }
}
int main()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        fin>>x>>y;
        contor[x].push_back(y);
        contor[y].push_back(x);
    }
    for(int i=1;i<=N;i++)
    {
        if(!viz[i])
        {
            nr++;
            DFS(i);
        }
    }
    fin.close();
    fout.close();
    return 0;
}