#include <fstream>

using namespace std;

const int N = 100001, M = 200001;

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

int n,m,vf[2*M],urm[2*M],lst[N],nr=0;

void adauga(int x,int y)
{
    vf[++nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}

bool viz[N];

void dfs(int x)
{
    viz[x]=true;
    for (int p=lst[x]; p!=0; p=urm[p])
    {
        int y=vf[p];
        if(!viz[y])
            dfs(y);
    }
}

int main()
{
    fin>>n>>m;
    for (int i=0; i<m; i++)
    {
        int x,y;
        fin>>x>>y;
        adauga(x,y);
        adauga(y,x);
    }
    int k = 0;
    for (int i=1; i<=n; i++)
    {
        if (!viz[i])
        {
            k++;
            dfs(i);
        }
    }
    fout<<k;
    return 0;
}