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

using namespace std;

int n,m,comp=0,viz[100005];
vector <int> V[100005];
ifstream fin("dfs.in");
ofstream fout("dfs.out");


void read()
{
    for(int i=1;i<=m;++i)
    {
        int x,y;
        fin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }

}

void DFS(int nod)
{
    viz[nod]=comp;
    for(int i=0;i<V[nod].size();++i)
        if(viz[V[nod][i]]==0)
            DFS(V[nod][i]);
}

int main()
{
    fin>>n>>m;
    read();
    for(int i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {
            comp++;
            DFS(i);
        }
    }
    fout<<comp;
    return 0;
}