#include <fstream>
#include <vector>

using namespace std;

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

vector <int> v[100001];
int n,m,i,viz[100001],x,y,nr;

void dfs(int x)
{
    for (int i: v[x])
    {
        if (!viz[i])
        {
            viz[i]=1;
            dfs(i);
        }
    }
}

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