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

ifstream cin("dfs.in");
ofstream cout("dfs.out");
int n,m,viz[100001],nr;
vector <int> G[100001];
void DFS(int start)
{
    viz[start]=1;
    for(unsigned int i=0; i<G[start].size(); ++i)
        if(!viz[G[start][i]])
            DFS(G[start][i]);
}
int main()
{
    cin>>n>>m;
    while(m--)
    {
        int x,y;
        cin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
            nr++,DFS(i);
    cout<<nr;
    return 0;
}