#include <fstream>
#include <vector>
#define NMax 100005

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

int N,M,Sol;
int Use[NMax];
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(unsigned int i = 0; i<G[Nod].size();i++)
        {
            int Vecin = G[Nod][i];
            if(!Use[Vecin])
                DFS(Vecin);
        }

}

void Solve()
{
    for(int i=1;i<=N;i++)
        if(!Use[i])
            {
                Sol++;
                DFS(i);
            }
}

void Print()
{
    fout<<Sol<<"\n";
}

int main()
{
    Read();
    Solve();
    Print();
    return 0;
}