#include <iostream>
#include <fstream>
#define vmax 100001
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
struct nod
{
    int y;
    nod *urm;
};
nod *lis[vmax],*p;
int n,m,i,j,viz[vmax],nrc=0;

void citire()
{
    f>>n>>m;
    while(f>>i>>j)
    {
        p = new nod;
        p->y = j;
        p->urm = lis[i];
        lis[i] = p;
        p = new nod;
        p->y = i;
        p->urm = lis[j];
        lis[j] = p;
    }
}

void dfs(int start)
{
    viz[start] = 1;
    nod *p;
    for(p=lis[start]; p!=NULL; p=p->urm)
        if(!viz[p->y])
            dfs(p->y);
}

int main()
{
    citire();
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
            cout << i;
            nrc++;
            dfs(i);
        }
    g << nrc;
    return 0;
}