#include <fstream>
#include <vector>
#define fin "dfs.in"
#define fout "dfs.out"
#define pb push_back
#define len 100010

using namespace std;
ifstream in(fin);
ofstream out(fout);
vector<int> v[len];
bool viz[len];
int n,m,x,y,cont;
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();++i)
        if(!viz[v[nod][i]])
            dfs(v[nod][i]);
}
int main()
{
    in>>n>>m;
    for(int k=0;k<m;++k)
    {
        in>>x>>y;
        v[x].pb(y);
        v[y].pb(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
        {
            dfs(i);
            ++cont;
        }
    out<<cont;
    return 0;
}