#include<iostream>
#include<fstream>
#include<vector>
#include<bitset>
#define dim 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> L[dim];
bitset <dim> fr;
int n,m,x,y,nr;
void dfs(int nod)
{
    fr[nod]=1;
    for(int i=0;i<L[nod].size();++i)
    {
        int vefin = L[nod][i];
        if(fr[vefin]==0)
        {
            dfs(vefin);
        }
    }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(y);

    }
    for(int i=1;i<=n;++i)
    {
        if(fr[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr;
    return 0;
}