#include <iostream>
#include <vector>
#include <fstream>

using namespace std;
vector <int> graf[100005];
int viz[100005],comp_conexe;
void DFS(int nod)
{
    int i,lim;
    viz[nod]=1;
    lim=graf[nod].size();
    for(i=0;i<lim;i++)
        if(viz[graf[nod][i]]==0)
        DFS(graf[nod][i]);
}
int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int i,N,M,x,y;
    in>>N>>M;
    for(i=1;i<=M;i++)
    {
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(i=1;i<=N;i++)
    {
        if(viz[i]==0)
        {
            DFS(i);
            comp_conexe++;
        }
    }
    out<<comp_conexe;
    return 0;
}