#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

#define maxN 100001
int viz[maxN];
vector <int> G[maxN];
int n,m;


void dfs(int nod)
{
    viz[nod]=1;
    for(unsigned int i=0;i<G[nod].size();++i)
        if(viz[G[nod][i]]==0)
            dfs(G[nod][i]);
}
int main()
{
    ifstream fin("dfs.in");
    ofstream gout("dfs.out");

    int x,y,nrc=0;
    fin>>n>>m;

    for(int i=0;i<m;++i)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=0;i<n;++i)
        if(viz[i+1]==0)
            dfs(i+1),nrc++;
    gout<<nrc;
    fin.close();
    gout.close();
    return 0;
}