#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
int const N=(int)1e5+4;
int c,n,m;
bool viz[N];
vector <int>v[N];
void citire()
{
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void dfs(int x)
{
    viz[x]=true;
    for(auto y:v[x])
        if(!viz[y])
            dfs(y);
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            c++;
        }
    cout<<c;
}