#include <bits/stdc++.h>

using namespace std;

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

int N,M;
int Grad[100005];
bool Viz[100005];
vector<int>Ad[100005];

void citire()
{
    int x,y;
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        fin>>x>>y;
        Ad[x].push_back(y);
        Ad[y].push_back(x);
        Grad[x]++;
        Grad[y]++;
    }
}

void DFS(int nod)
{
    Viz[nod]=1;
    for(int i=0;i<Grad[nod];i++)
        if(!Viz[Ad[nod][i]])
            DFS(Ad[nod][i]);
}

int main()
{
    unsigned componenteConexe=0;
    citire();
    for(int i=1;i<=N;i++)
    {
        if(!Viz[i])
        {
            componenteConexe++;
            DFS(i);
        }
    }
    fout<<componenteConexe;
    return 0;
}