#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream fin("vector.in");
ifstream fout("vector.out");
const int NMax=100005;
int N, M;
vector <int> G[NMax];
bool Use[100005];
struct Muchie
{
    int x, y;
};
Muchie E[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<G[Nod].size();i++)
    {
        int Next=G[Nod][i];
        if(Use[Next]==0)
            DFS(Next);
    }
}

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