#include<fstream>
#include<vector>
#define nmax 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[nmax];
int n,m,nrsol,viz[nmax];
void citire()
{
    int x,y;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void DFS(int x)
{
    viz[x]=1;
    for(int i=0;i<v[x].size();i++)
        if(!viz[v[x][i]])
            DFS(v[x][i]);
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            DFS(i);
            nrsol++;
        }
    fout<<nrsol;
    return 0;
}