#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
#define mxn 100010
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> vecini[mxn];
int i,v[mxn];
void citire (int &n, int &m)
{
    int x,y;
    f>>n>>m;
    for(i=0;i<m;i++)
    {
        f>>x>>y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
}
void dfs (int nod)
{
    v[nod]=1;
    for(vector<int>::iterator it = vecini[nod].begin(); it!= vecini[nod].end(); ++it)
    {
        if(v[*it]!=1)
            dfs(*it);
    }
}
int main()
{
    int n,m,nr=0;
    citire(n,m);
    for(i=1;i<=n;i++)
    {
        if(v[i]!=1)
        {
            dfs(i);
            nr++;
        }
    }
    g<<nr;
    return 0;
}