#include <fstream>
#include <vector>

using namespace std;

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

const int n_max=100005;
int m,n,viz[n_max];
vector<int> v[n_max];

void citire()
{
    fin>>n>>m;
    int x,y;
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=1;i<v[nod].size();++i)
    {
        if(viz[v[nod][i]]==0)
        {
            viz[v[nod][i]]=1;
            dfs(v[nod][i]);
        }

    }
}

int main()
{
    citire();
    int cnt=0;
    for(int i=1;i<=n;++i)
    if(viz[i]==0)
    {
        cnt++;
        dfs(i);
    }
    fout<<cnt;
    return 0;
}