#include<iostream>
#include<fstream>
#include<cstdio>
#include<vector>
#include<cstring>
#include<algorithm>

#define NMAX 100001
using namespace std;

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

vector<int>a[NMAX];
int viz[NMAX];
int n;

void read()
{
    int x,y,m,i;
    memset(viz, 0, sizeof(viz));
    in>>n>>m;
    for (i=1;i<=m;++i)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}


void DFS(int nod)
{
    viz[nod]=1;
    for(unsigned int j=0;j<a[nod].size();++j)
        if (viz[a[nod][j]]==0)
        {
            DFS(a[nod][j]);

        }
}

int main (void)
{
    read();
    int count=0;
    for(int i=1;i<=n;++i)
        if (viz[i]==0)
        {
            count++;
            DFS(i);
        }
    out<<count<<'\n';
    for(int i=1;i<=n;++i)
    {

        for(int j=0;j<a[i].size();++j);
          //  cout<<a[i][j]<<" ";
       // cout<<endl;
    }
    in.close();
    out.close();
    return 0;

}