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

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int N=100005;
vector <int> g[N];
bool v[N];
int n,m;

void citire()
{
    cin>>n>>m;
    int x,y;
    for(int i=0; i<m; i++)
    {
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}
void dfs(int k)
{
    v[k]=1;
    for(auto i:g[k])
        if(v[i]==0)
        dfs(i);
}
int main()
{
    citire();
    int nr=0;
    for(int i=1;i<=n;i++)
        if(v[i]==0)
        {
            dfs(i);
            nr++;
        }
    cout<<nr;
    return 0;
}