#include<bits/stdc++.h>

using namespace std;

const int nmax = 100001;

class GRAF
{
private:
    int n, m, s;
    vector<int> v[nmax];

public:
    GRAF(bool orientat);
    void bfs();
    void dfs(int poz, bool viz[]);
    void conex();
};

GRAF::GRAF(bool orientat)
{
    //freopen("bfs.in", "r", stdin);
    //scanf("%d %d %d", &n, &m, &s);
    freopen("dfs.in", "r", stdin);
    scanf("%d %d", &n, &m);
    int x, y;
    for(int i=0; i<m; ++i)
    {
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        if(!orientat)
            v[y].push_back(x);
    }
    fclose(stdin);
}

void GRAF::bfs()
{
    int d[n+1];
    fill_n(d, n+1, -1);
    d[s] = 0;
    queue<int> q;
    q.push(s);
    while(!q.empty())
    {
        int poz = q.front();
        for(auto i : v[poz])
        {
            if(d[i] == -1)
            {
                q.push(i);
                d[i]=d[poz]+1;
            }
        }
        q.pop();
    }
    freopen("bfs.out", "w", stdout);
    for(int i=1; i<=n; ++i)
        printf("%d ", d[i]);
    fclose(stdout);
}

void GRAF::dfs(int poz, bool viz[])
{
    viz[poz] = true;
    for(auto i : v[poz])
    {
        if(!viz[i])
            dfs(i, viz);
    }
}

void GRAF::conex()
{
    bool viz[n+1] = {false};
    int nrconex = 0;

    for(int i=1; i<=n; ++i)
    {
        if(!viz[i])
        {
            dfs(i, viz);
            nrconex++;
        }
    }
    freopen("dfs.out", "w", stdout);
    printf("%d", nrconex);
    fclose(stdout);
}



int main()
{
    GRAF g(false);
    g.conex();
    return 0;
}