#include <fstream>
#include <vector>
using namespace std;
ifstream in ("dfs.in");
ofstream out ("dfs.out");

const int NMAX = 100000;
int n,m,x,y,viz[NMAX+10],ans;
vector <int> g[NMAX+10];

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

int main()
{
    in>>n>>m;

    for(int i = 1 ; i <= m ; i++)
    {
        in>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i = 1 ; i <= n ; i++)
    {
        if(viz[i] == 0)
        {
            DFS(i);
            ans++;
        }
    }
    out<<ans<<"\n";
    return 0;
}