#include<cstdio>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<bitset>
#include<list>
using namespace std;
bitset<100005> x;
list<int> g[100005];
void dfs(int s)
{
    x[s]=1;
    list<int>::iterator i;
    for(i=g[s].begin();i!=g[s].end();++i)
    {
        if(x[*i]==0)
        {
            dfs(*i);
        }
    }

}
int main()
{
    //ifstream si;
    //si.open("numere.in");
    FILE* si=fopen("dfs.in","r");
    //FILE* so=fopen("simetric1.out","w");
    ofstream so;
    so.open("dfs.out");

    int m,n;
    fscanf(si,"%i %i",&n,&m);
    int i,a,b;
    for(i=0;i<m;++i)
    {
        fscanf(si,"%i %i",&a,&b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
    int cont=0;
    for(i=1;i<=n;++i)
    {
        if(x[i]==0)
        {
            ++cont;
            dfs(i);
        }
    }
    so<<cont<<'\n';
}