#include <bits/stdc++.h>
#define NMax 100001

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");


bool vizDFS[NMax];


class graf
{
   int nrNoduri, nrMuchii;
   bool orientat;
   vector <int> gr[NMax]; // liste de adiacenta

public:
    graf(int n, int m, bool o); // constructor
    void Citire_Orientat();
    void Citire_Neorientat();
    void BFS(int s); // s - nodul de start
    void DFS(int s); // s - nodul de start
    void Comp_Conexe();
};


graf :: graf(int n, int m, bool o)
{
    nrNoduri = n;
    nrMuchii = m;
    orientat = o;
}

void graf :: Citire_Orientat()
{
    for(int i = 1; i <= nrMuchii; ++i)
    {
        int x, y;
        fin >> x >> y;
        gr[x].push_back(y);
    }
}

void graf :: Citire_Neorientat()
{
    for(int i = 1; i <= nrMuchii; ++i)
    {
        int x, y;
        fin >> x >> y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }
}

void graf :: BFS(int s)
{
    bool viz[NMax] = {0};
    int distanta[NMax] = {0};
    queue <int> q;

    viz[s] = 1;
    q.push(s);

    while(!q.empty())
    {
        int k = q.front(); // elem din varful cozii
        q.pop(); // sterg elem din varful cozii
        for(auto i : gr[k])
            if(!viz[i])
            {
                viz[i] = 1;
                q.push(i);
                distanta[i] = distanta[k] + 1;
            }
    }

    for(int i = 1; i <= nrNoduri; ++i)
        if(viz[i])
            fout << distanta[i] << " ";
        else
            fout << -1 << " ";
}

void graf :: DFS(int s)
{
    vizDFS[s] = 1;
    for(auto i : gr[s])
        if(!vizDFS[i])
            DFS(i);
}

void graf :: Comp_Conexe()
{
    int ct = 0;
    for(int i = 1; i <= nrNoduri; ++i)
        if(!vizDFS[i])
            {
                ct++;
                DFS(i);
            }
    fout << ct;
}


int nrNoduri, nrMuchii;

int main()
{
    fin >> nrNoduri >> nrMuchii;
    graf G(nrNoduri, nrMuchii, 0);
    G.Citire_Neorientat();
    G.Comp_Conexe();

    return 0;
}