#include <fstream>
#include <vector>
using namespace std;

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

long n,i,nr,m,j,x,y,d[100005];
vector <int> v[100005];

void dfs(long nod)
{
    d[nod]=1;
    for (int i=0;i<v[nod].size();i++)
        if (d[v[nod][i]]==0)
            dfs(v[nod][i]);
}
int main()
{
    f>>n>>m;
    for (i=1;i<=m;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (i=1;i<=n;i++)
        if (d[i]==0)
        {
            dfs(i);
            nr++;
        }

    g<<nr;

    f.close();
    g.close();
    return 0;
}