#include <fstream>
#include <vector>
#define nmax 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int> a[nmax];
bool viz[nmax];
int n,m;

void citire()
{
    int i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int nod)
{
    int i;
    viz[nod]=true;
    for(i=0;i<a[nod].size();i++)
        if(viz[a[nod][i]]==false)
            dfs(a[nod][i]);
}

int main()
{
    int nrc=0,i;
    citire();
    for(i=1;i<=n;i++)
        if(viz[i]==false)
        {
            nrc++;
            dfs(i);
        }
    fout<<nrc;
    return 0;
}