#include <fstream>
#include <bitset>
#include <vector>
#define nmax 100005
using namespace std;
typedef unsigned int nat;
vector <nat> a[nmax];
bitset <nmax> viz;
void df(nat x)
{
    nat y,i;
    viz[x]=1;
    for (i=0;i<a[x].size();i++)
    {
        y=a[x][i];
        if ( !viz[y] )
            df(y);
    }
}
int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    nat n,m,i,x,y,comp=0;
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (i=1;i<=n;i++)
        if (!viz[i]) df(i),comp++;
    fout<<comp<<'\n';
    fin.close();
    fout.close();
    return 0;
}