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

ifstream fin("dfs.in");
ofstream fout("dfs.out");

struct nod{
                bool used;
                vector<int> v;
          }p[100001];

int n, m;

void dfs(int x)
{
    p[x].used=1;
    for(int i=0;i<p[x].v.size();++i)
        if(!p[p[x].v[i]].used) dfs(p[x].v[i]);
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        int x, y;
        fin>>x>>y;
        p[x].v.push_back(y);
        p[y].v.push_back(x);
    }
    int nr=0;
    for(int i=1;i<=n;++i)
        if(!p[i].used) nr++, dfs(i);
    fout<<nr<<"\n";
    return 0;
}