#include <bits/stdc++.h>
using  namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int nmax=100005;
int n,m,viz[nmax],fin;
vector <int> L[nmax];
void DFS(int nod)
{
    viz[nod]=1;
    for (auto k:L[nod])
    {
        if (viz[k]==0)DFS(k);
    }
}
int main()
{
    in>>n>>m;
    int i,a,b;
    for (i=1;i<=m;i++)
    {
        in>>a>>b;
        L[a].push_back(b);
        L[b].push_back(a);
    }
    for (i=1;i<=n;i++)
    {
        if (viz[i]==0)
        {
            DFS(i);
            fin++;
        }
    }
    out<<fin<<"\n";
    out.close();
    in.close();
    return 0;
}