#include <fstream>
#include <vector>

#define NMAX 100005

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector<int> graf[NMAX];
int n,m,viz[NMAX],sol;

void citire()
{
    int x,y;
    f>>n>>m;
    while(m)
    {
        f>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
        m--;
    }
}

void DFS(int start)
{
    viz[start]=1;
    for(unsigned int i=0;i<graf[start].size();i++)
        if(viz[graf[start][i]]==0)
            DFS(graf[start][i]);
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
            DFS(i);
            sol++;
        }
    g<<sol;
    return 0;
}