#include <fstream>
#include <vector>

using namespace std;
ifstream cin ("dfs.in");
ofstream cout ("dfs.out");
vector <int> muchii[100005];
int n,m,x,y,viz[100005],cnt,vecin;
void dfs(int nod)
{
    viz[nod]=1;
    for (int i=0;i<muchii[nod].size();i++)
    {
        vecin=muchii[nod][i];
        if (viz[vecin]==0) dfs(vecin);
    }
}
int main()
{
    cin >> n>>m;
    for (int i=1;i<=m;i++)
    {
        cin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (int i=1;i<=n;i++)
    {
        if (viz[i]==0)
            dfs(i),cnt++;
    }
    cout << cnt;
    return 0;
}