#include <iostream>
#include<vector>
#include<fstream>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> Muchii[100001];
bool vizitat[100001];
int x,y,N,M;
int insule;
void DFS(int Node)
{
    vizitat[Node] = true;
    for(unsigned int i = 0; i < Muchii[Node].size(); i++)
    {
        int Next = Muchii[Node][i];
        if(!vizitat[Next])
            DFS(Next);
    }
}

int main()
{
    f>>N>>M;
    for(int i=0;i<M;i++)
    {
        f>>x>>y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }

    for(int i=1;i<=N;i++)
    {
        if(!vizitat[i])
        {
            insule++;
            DFS(i);
        }
    }
    g<< insule;
    return 0;
}