#include<fstream>
#include<vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int>l[100001];
int v[100001],i,n,m,x,y,nr;
void dfs(int nod)
{
    v[nod]=1;
    for(i=0;i<l[nod].size();++i)
        if(v[l[nod][i]]==0)
            dfs(l[nod][i]);

}
int main()
{
    in>>n>>m;
    for (i=0;i<m;++i)
    {
        in>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);

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