#include <fstream>
#include <vector>

using namespace std;

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

int N,M,sol,viz[100000];
vector <int> A[100000];

void parcurgereDFS(int x)
{
    viz[x]=1;
    for(int i=0;i<A[x].size();++i)
        if (!viz[A[x][i]])
            parcurgereDFS(A[x][i]);
}

void citire()
{
    in>>N>>M;
    for(int x,y,i=1;i<=M;++i)
    {
        in>>x>>y;
        A[x].push_back(y);
        A[y].push_back(x);
    }
}

int main()
{
    citire();
    for(int i=1;i<=N;++i)
    {
        if(!viz[i])
        {
            sol++;
            parcurgereDFS(i);
        }
    }
    out<<sol<<'\n';
    return 0;
}