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

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

const int NMax = 100005;
vector <int> G[NMax];
int N,M;
int Use[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])
            DFS(Vecin);
    }
}

int main()
{
    int contor = 0;
    Read();
    for(int i = 1; i <= N; ++i){
        if(!Use[i]){
            contor++;
            DFS(i);
        }
    }
    out << contor << "\n";
    return 0;
}