#include <iostream>
#include <vector>
using namespace std;
vector <int> v[100005];
int n,m;
int a,b,cnt;
int viz[100005];
void dfs(int nod)
{
    viz[nod]=1;
    for(auto i :v[nod])
        if(!viz[i])
            dfs(i);
}
int main()
{
    cin>>n>>m;
    for(int i=1;i<=m;++i)
    {
       cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
    {
        dfs(i);
        ++cnt;
    }
    cout<<cnt;
    return 0;
}