#include <fstream>
#include <vector>
#define MX 100005

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n,m,viz[MX];
vector <int> V[MX];

void DFS(int nod)
{
    viz[nod]=1;
    for(vector <int>::iterator it=V[nod].begin();it!=V[nod].end();++it)
    if(viz[*it]==0)
    DFS(*it);
}

int main()
{
    int cnt=0,x,y;
    fin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }

    for(int i=1;i<=n;++i)
    viz[i]=0;

    for(int i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {DFS(i);
        ++cnt;}
    }

    fout<<cnt<<'\n';

    return 0;
}