#include<iostream>
#include<fstream>
#include<vector>
#define nmax 100010
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,viz[nmax],nr;
vector<int>G[nmax];
void dfs(int nod,int nr)
{
    viz[nod]=1;
    for(vector<int> :: iterator it= G[nod].begin();it!=G[nod].end();++it)
    {
        if(!viz[*it])
        {
            dfs(*it,nr);
        }
    }
}
int main()
{
    int x,y,i;
    fin>>n>>m;
    while(m--)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            nr++;
            dfs(i,nr);
        }
    }
    fout<<nr;
    fin.close();
    fout.close();
    return 0;
}