#include <fstream>
#include <vector>
#define nmax 100004
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,x,y,counter;
bool seen[nmax];
vector <int> G[nmax];

void dfs (int node)
{
    seen[node]=1;
    for (auto ne:G[node])
        if (seen[ne]==0) dfs(ne);
}


int main()
{
    f>>n>>m;
    for (int i=1;i<=m;i++)
    {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i=1;i<=n;i++)
        if (seen[i]==0)
        {
            dfs(i);
            counter++;
        }

    g<<counter;

    f.close();
    g.close();
    return 0;
}