#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NMax=100005;

int N,M,Use[NMax],contor;
vector <int> G[NMax];

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

void DFS(int Nod)
{
    Use[Nod]=1;
    for(int i=0;i<(int)G[Nod].size();i++)
        {
            int Vecin=G[Nod][i];
            if(Use[Vecin]==0)
                DFS(Vecin);
        }
}

int main()
{
    Read();
    for(int i=1;i<=N;i++)
    {
        if(Use[i]==0)
        {
            DFS(i);
            contor++;
        }
    }
    fout<<contor;
    return 0;
}