#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,v[100001],componente_conexe;
vector <int> ma[100001];
void DFS(int nod)
{
    v[nod]=1;
    for(int i=0;i<ma[nod].size();i++)
        if(v[ma[nod][i]]==0)
            DFS(ma[nod][i]);
}

int main()
{
    int x,y;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        ma[x].push_back(y);
        ma[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(v[i]==0)
    {
        DFS(i);
        componente_conexe++;
    }
    fout<<componente_conexe;
    return 0;
}