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

const int N = 1e5;

vector <int> a[N+1] ; // liste de adiacenta
int nr = 0;
bool viz[N+1];

void dfs(int x)
{
    viz[x]=true;
    for(auto y:a[x])
    {
        if(!viz[y])
            dfs(y);
    }
}

int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");

    int n;
    long long m;
    in>>n>>m;
    int x,y;
    while(in>>x>>y)
    {
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(int i = 1 ; i <= n ;i++)
    {
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    }
    out<<nr;
    in.close();
    out.close();
    return 0;
}